Parenteral Preparations

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Sample chapter rom Remington: Essentials o Pharmaceutics

Chapter 26

P PpoMichael J. Akers, Ph

Parenteral (Gk, para enteron, beside the intestine) dosageorms dier rom all other drug dosage orms, because theyare injected directly into body tissue through the primaryprotective systems o the human body, the skin, and mucousmembranes. They must be exceptionally pure and ree romphysical, chemical, and biological contaminants. These re-quirements place a heavy responsibility on the pharmaceuti-cal industry to practice current good manuacturing practices(cGMPs) in the manuacture o parenteral dosage orms andon pharmacists and other health care proessionals to practicegood aseptic practices (GAPs) in dispensing parenteral dosageorms or administration to patients.

Certain pharmaceutical agents, particularly peptides, pro-teins, and many chemotherapeutic agents, can only be givenparenterally, because they are inactivated in the gastrointes-

tinal tract when given by mouth. Parenterally-administereddrugs are relatively unstable and generally highly potent drugsthat require strict control o administration to the patient. Dueto the advent o biotechnology, parenteral products have grownin number and usage around the world.

This chapter ocuses on the unique characteristics o par-enteral dosage orms and the basic principles or ormulating,packaging, manuacturing, and controlling the quality o theseunique products. The reerences and bibliography at the end o this chapter contain the most up-to-date texts, book chapters,and review papers on parenteral product ormulation, manuac-ture, and quality control.

Overview O UniqUe CharaCteristiCsO Parenteral DOsage Orms

Parenteral products are unique rom any other type o pharmaceutical dosage orm or the ollowing reasons:

• All products must be sterile.• All products must be ree rom pyrogenic (endotoxin) co

tamination.• Injectable solutions must be ree rom visible particulate

matter. This includes reconstituted sterile powders.• Products should be isotonic, although strictness o isoto-

nicity depends on the route o administration. Productsadministered into the cerebrospinal uid must be isotonic. Ophthalmic products, although not parenteral, mustalso be isotonic. Products to be administered by bolusinjection by routes other than intravenous (IV) should beisotonic, or at least very close to isotonicity. IV inusionsmust be isotonic.

• All products must be stable, not only chemically andphysically like all other dosage orms, but also ‘stable’microbiologically (i.e., sterility, reedom rom pyrogenicand visible particulate contamination must be maintainethroughout the shel lie o the product).

• Products must be compatible, i applicable, with IV diluents, delivery systems, and other drug productsco-administered.

Overview O UniqUe CharaCteristiCsO Parenteral DOsage Orms 495

OrmUlatiOn PrinCiPles 496

vehiCles 496

sOlUtes 496

aDministratiOn 499

Parenteral COmbinatiOns 499

general COnsiDeratiOns 499

general manUaCtUring PrOCess 500

COmPOnents 501

water Or injeCtiOn (wi) 501

COntainers anD ClOsUres 504

COntainer tyPes 504

rUbber ClOsUres 506

neeDles 508

PyrOgens (enDOtOxins) 509

PrODUCtiOn aCilities 510

UnCtiOnal areas 510

maintenanCe O Clean rOOms 514

PersOnnel 514

envirOnmental COntrOl evalUatiOn 515

PrODUCtiOn PrOCeDUres 517

Cleaning COntainers anD eqUiPment 517

PrODUCt PreParatiOn 519

iltratiOn 520

illing 521

sealing 523

sterilizatiOn 524

reeze-Drying (lyOPhilizatiOn) 525

qUality assUranCe anD COntrOl 528

sterility test 528

PyrOgen test 529

PartiCUlate matter evalUatiOn 529

COntainer/ClOsUre integrity test 530

saety test 530

PaCkaging anD labeling 530



496 PHARMACEUTICAL DOSAGE FORMS: MAnUFACTURInG AnD COMPOUnDInG


OrmUlatiOn PrinCiPles

Parenteral drugs are ormulated as solutions, suspensions,emulsions, liposomes, microspheres, nanosystems, and pow-ders to be reconstituted as solutions. This section describes thecomponents commonly used in parenteral ormulations, ocus-ing on solutions and reeze-dried products. General guidance isprovided on appropriate selection o the fnished sterile dosageorm and initial approaches used to develop the optimal paren-teral ormulation.

vehiCles

water

Since most liquid injections are quite dilute, the componentpresent in the highest proportion is the vehicle. The vehicle o greatest importance or parenteral products is water. Water o suitable quality or compounding and rinsing product contactsuraces, to meet United States Pharmacopeia (USP) and othercompendia specifcations or Water or Injection (WFI), maybe prepared either by distillation or by reverse osmosis. Onlyby these two methods is it possible to separate various liquid,gas, and solid contaminating substances rom water. These twomethods or preparation o WFI and specifcations or WFI arealso discussed in this chapter. With the possible exception o reeze-drying, there is no unit operation more important andnone more costly to install and operate than that or the prepa-ration o WFI.

water-misCible vehiCles

A number o solvents that are miscible with water have beenused as a portion o the vehicle in the ormulation o parenter-als. These solvents are used to solubilize certain drugs in anaqueous vehicle and to reduce hydrolysis. The most impor-tant solvents in this group are ethyl alcohol, liquid polyethyl-ene glycol, and propylene glycol. Ethyl alcohol is used in thepreparation o solutions o cardiac glycosides and the glycolsin solutions o barbiturates, certain alkaloids, and certain an-tibiotics. Such preparations are given intramuscularly. Thereare limitations with the amount o these co-solvents that canbe administered, due to toxicity concerns, greater potential or

hemolysis, and potential or drug precipitation at the site o injection.1 Formulation scientists needing to use one or more o these solvents must consult the literature (e.g., Mottu F et al. 2000)2 and toxicologists to ascertain the maximum amount o co-solvents allowed or their particular product. Several reer-ences provide inormation on concentrations o co-solventsused in approved commercial parenteral products.3–8

nOn-aqUeOUs vehiCles

The most important group o non-aqueous vehicles is the fxedoils. The USP provides specifcations or such vehicles, indi-cating that the fxed oils must be o vegetable origin so theywill metabolize, will be liquid at room temperature, and willnot become rancid readily. The USP also specifes limits or theree atty acid content, iodine value, and saponifcation value(oil heated with alkali to produce soap, i.e., alcohol plus acid

salt). The oils most commonly used are corn oil, cottonseed oil,peanut oil, and sesame oil. Fixed oils are used as vehicles orcertain hormone (e.g., progesterone, testosterone, deoxycorti-cicosterone) and vitamin (e.g., Vitamin K, Vitamin E) prepara-tions. The label must state the name o the vehicle, so the usermay beware in case o known sensitivity or other reactions to it.

sOlUtes

Care must be taken in selecting active pharmaceutical ingredi-ents and excipients to ensure their quality is suitable or par-enteral administration. A low microbial level will enhance theeectiveness o either the aseptic or the terminal sterilization

process used or the drug product.Likewise, nonpyrogenic in-gredients enhance the nonpyrogenicity o the fnished inject-able product. It is now a common GMP procedure to establishmicrobial and endotoxin limits on active pharmaceutical in-gredients and most excipients. Chemical impurities should bevirtually nonexistent in active pharmaceutical ingredients orparenterals, because impurities are not likely to be removedby the processing o the product. Depending on the chemicalinvolved, even trace residues may be harmul to the patient orcause stability problems in the product. Thereore, manuactur-ers should use the best grade o chemicals obtainable and use

its analytical profle to determine that each lot o chemical usedin the ormulation meets the required specifcations.

Reputable chemical manuacturers accept the stringentquality requirements or parenteral products and, accord-ingly, apply good manuacturing practices to their chemicalmanuacturing. Examples o critical bulk manuacturing pre-cautions include:

• Using dedicated equipment or properly validated cleaningto prevent cross-contamination and transer o impurities;

• Using WFI or rinsing equipment;• Using closed systems, wherever possible, or bulk manu-

acturing steps not ollowed by urther purifcation; and• Adhering to specifed endotoxin and bioburden testing

limits or the substance.

aDDeD sUbstanCes

The USP includes in this category all substances added to apreparation to improve or saeguard its quality. An added sub-stance may:

• Increase and maintain drug solubility. Examples includecomplexing agents and surace active agents. The mostcommonly used complexing agents are the cyclodextrins,including Captisol. The most commonly used suraceactive agents are polyoxyethylene sorbitan monolaurate(Tween 20) and polyoxyethylene sorbitan monooleate(Tween 80).

• Provide patient comort by reducing pain and tissue irrita-tion, as do substances added to make a solution isotonicor near physiological pH. Common tonicity adjusters are

sodium chloride, dextrose, and glycerin.• Enhance the chemical stability o a solution, as do anti-

oxidants, inert gases, chelating agents, and buers.• Enhance the chemical and physical stability o a reeze-

dried product, as do cryoprotectants and lyoprotectants.Common protectants include sugars, such as sucrose andtrehalose, and amino acids, such as glycine.

• Enhance the physical stability o proteins by minimizingsel-aggregation or interacial induced aggregation. Suraceactive agents serve nicely in this capacity.

• Minimize protein interaction with inert suraces, such asglass and rubber and plastic. Competitive binders, such asalbumin, and surace active agents are the best examples.

• Protect a preparation against the growth o microorgan-isms. The term ‘preservative’ is sometimes applied onlyto those substances that prevent the growth o microor-

ganisms in a preparation. However, such limited use isinappropriate, being better used or all substances that actto retard or prevent the chemical, physical, or biologicaldegradation o a preparation.

• Although not covered in this chapter, other reasonsor adding solutes to parenteral ormulations includesustaining and/or controlling drug release (polymers),maintaining the drug in a suspension dosage orm(suspending agents, usually polymers and surace activeagents), establishing emulsifed dosage orms (emulsiy-ing agents, usually amphiphilic polymers and suraceactive agents), and preparation o l iposomes (hydratedphospholipids).



49PAREnTERAL PREPARATIOnS


Although added substances may prevent a certain reactionrom taking place, they may induce others. Not only may visibleincompatibilities occur, but hydrolysis, complexation, oxida-tion, and other invisible reactions may decompose or otherwiseinactivate the therapeutic agent or other added substances.9 Thereore, added substances must be selected with due consid-eration and investigation o their eect on the total ormulationand the container-closure system.

antimiCrObial agents

The USP states that antimicrobial agents in bacteriostatic or

ungistatic concentrations must be added to preparations con-tained in multiple-dose containers. The European Pharmaco-peia requires multiple-dose products to be bacteriocidal andungicidal. They must be present in adequate concentration atthe time o use to prevent the multiplication o microorganismsinadvertently introduced into the preparation, while withdraw-ing a portion o the contents with a hypodermic needle andsyringe. The USP provides a test or Antimicrobial PreservativeEectiveness to determine that an antimicrobial substance orcombination adequately inhibits the growth o microorganismsin a parenteral product.10 Because antimicrobials may have in-herent toxicity or the patient, the USP prescribes maximumvolume and concentration limits or those commonly used inparenteral products (e.g., phenylmercuric nitrate and thimero-sal 0.01%, benzethonium chloride and benzalkonium chloride

0.01%, phenol or cresol 0.5%, and chlorobutanol 0.5%).The above limit is rarely used or phenylmercuric nitrate,most requently employed in a concentration o 0.002%. Meth-yl p-hydroxybenzoate 0.18% and propyl p-hydroxybenzoate0.02%, in combination, and benzyl alcohol 2% are also used re-quently. Benzyl alcohol, phenol, and the parabens are the mostwidely used antimicrobial preservative agents used in inject-able products. Although the mercurials are still allowed to beused in older products, they are not used or new products, dueto concerns regarding mercury toxicity. In oleaginous prepara-tions, no antibacterial agent commonly employed appears tobe eective. However, it has been reported that hexylresorcinol0.5% and phenylmercuric benzoate 0.1% are moderately bacte-ricidal. A ew therapeutic compounds have been shown to haveantibacterial activity, thus, obviating the need or added agents.

Antimicrobial agents must be studied with respect to compat-

ibility with all other components o the ormula. In addition,their activity must be evaluated in the total ormula. It is notuncommon to fnd a particular agent eective in one ormu-lation but ineective in another, possibly due to the eect o various components o the ormula on the biological activityor availability o the compound; or example, the binding andinactivation o esters o p-hydroxybenzoic acid by macromol-ecules, such as Polysorbate 80, or the reduction o phenylmer-curic nitrate by sulfde residues in rubber closures. A physicalreaction encountered is that bacteriostatic agents are some-times removed rom solution by rubber closures.

Protein pharmaceuticals, because o their cost and/or re-quency o use, are preerred to be available as multiple doseormulations (e.g., Human Insulin, Human Growth Hormone,Intererons, Vaccines, etc.). However, several proteins are re-active with antimicrobial preservative agents (e.g., Tissue

Plasminogen Activator, Sargramostim, and Interleukins) and,thereore, are only available as single dosage units. Phenol andbenzyl alcohol are the two most common antimicrobial preser-vatives used in peptide and protein products. Phenoxyethanolis the most requently used preservative in vaccine products.

Single-dose containers and pharmacy bulk packs that do notcontain antimicrobial agents are expected to be used promptlyater opening or discarded. The ICH/CPMP guidelines (http:// www.ema.europa.eu/docs/en_GB/document_library/Scientifc_guideline/2009/09/WC500003476.pd) require that productswithout preservatives be used immediately, although somepackage inserts defne immediate use as within 3 hours aterentering the primary package, or a longer usage period must be

justifed. Large-volume, single-dose containers may not contaan added antimicrobial preservative. Thereore, special carmust be exercised in storing such products ater the containehave been opened to prepare an admixture, particularly thosthat support the growth o microorganisms, such as total paenteral nutrition (TPN) solutions and emulsions. It should bnoted that, although rerigeration slows the growth o most mcroorganisms, it does not prevent their growth.

Buers are used to stabilize a solution against chemical degradation or, especially or proteins, physical degradation (i.e., agregation and precipitation) which might occur i the pH change

appreciably. Buer systems should have as low a buering capacity as easible, so as not to signifcantly disturb the bodybuering systems when injected. In addition, the buer type anconcentration on the activity o the active ingredient must bevaluated careully. Buer components are known to catalyzdegradation o drugs. The acid salts most requently employeas buers are citrates, acetates, and phosphates. Amino acid buers, especially histidine, have become buer systems o choicor controlling solution pH o monoclonal antibody solutions. Anitoxidants are requently required to preserve product

due to the ease with which many drugs, including proteins witmethionine or cysteine amino acids conormationally exposeare oxidized. Sodium bisulfte and other sulurous acid salts arused most requently. Ascorbic acid and its salts are also gooantioxidants. The sodium salt o ethylenediaminetetraacet

acid (EDTA) has been ound to enhance the activity o antoxidants, in some cases, by chelating metallic ions that wouotherwise catalyze the oxidation reaction.

Displacing the air (oxygen) in and above the solution, by puring with an inert gas, such as nitrogen, can also be used as means to control oxidation o a sensitive drug. Process contris required or assurance that every container is deaerated aequately and uniormly. However, conventional processes oremoving oxygen rom liquids and containers do not absoluteremove all oxygen. The only approach or completely removinoxygen is to employ isolator technology, where the entire atmsphere can be recirculating nitrogen or another non-oxygen ga

Tonicity Agents are used in many parenteral and ophthalmproducts to adjust the tonicity o the solution. Although it is thgoal or every injectable product to be isotonic with physiologuids, this is not an essential requirement or small volum

injectables administered intravenously. However, products aministered by all other routes, especially into the eye or spinuid, must be isotonic. Injections into the subcutaneous tissuand muscles should also be isotonic to minimize pain and tissuirritation. The agents most commonly used are electrolytes anmono- or disaccharides.

Cryoprotectants and Lyoprotectants are additives that servto protect biopharmaceuticals rom adverse eects, due reezing and/or drying o the product during reeze-dry procesing. Sugars (non-reducing), such as sucrose or trehalose, aminacids, such as glycine or lysine, polymers, such as liquid polyethylene glycol or dextran, and polyols, such as mannitol or sobitol, all are possible cryo- or lyoprotectants. Several theorieexist to explain why these additives work to protect proteinagainst reezing and/or drying eects.11,12 Excipients that apreerentially excluded rom the surace o the protein are th

best cryoprotectants, and excipients that remain amorphouduring and ater reeze-drying serve best as lyoprotectants.

general gUiDanCe Or DevelOPingOrmUlatiOns O Parenteral DrUgs

The fnal ormulation o a parenteral drug product depends ounderstanding the ollowing actors that dictate the choice ormulation and dosage orm.

1. Route o administration—Injections may be admin-istered by such routes as intravenous, subcutaneous,intradermal, intramuscular, intraarticular, intralesional,and intrathecal. The type o dosage orm (solution,





suspension, etc.) determines the particular route o administration employed. Conversely, the desired routeo administration places requirements on the ormula-tion. For example, suspensions would not be adminis-tered directly into the bloodstream, due to the danger o insoluble particles blocking capillaries. Solutions admin-istered subcutaneously require strict attention to tonicityadjustment, otherwise irritation o the plentiul supplyo nerve endings in this anatomical area would give riseto pronounced pain. Injections intended or intraocular,intraspinal, intracisternal, and intrathecal administration

require stricter standards o such properties as ormula-tion tonicity, component purity, and limit o endotoxins,due to the sensitivity o tissues encountered to irritantand toxic substances.

2. I the route o administration must be intravenous, thenonly solutions or microemulsions can be the dosage orm.I the route o administration is subcutaneous or intra-muscular, then the likely type o dosage orm is a suspen-sion or other microparticulate delivery system.

3. Pharmacokinetics o the drug—Rates o absorption (orroutes o administration other than intravenous or intra-arterial), distribution, metabolism, and excretion or adrug have some eect on the selected route o admin-istration and, accordingly, the type o ormulation. Forexample, i the pharmacokinetic profle o a drug is very

rapid, modifed release dosage ormulations may needdeveloped. The dose o drug and the dosage regimen areaected by pharmacokinetics, so the size (i.e., concentra-tion) o the dose will also inuence the type o ormulationand amounts o other ingredients in the ormulation. I thedosage regimen requires requent injections, then a mul-tiple dose ormulation must be developed, i easible. I thedrug is distributed quickly rom the site injection, com-plexing agents or viscosity inducing agents may be addedto the ormulation to retard drug dissolution and transport.

4. Drug solubility—I the drug is insufciently soluble inwater at the required dosage, then the ormulation mustcontain a co-solvent or a solute that sufciently increasesand maintains the drug in solution. I relatively simpleormulation additives do not result in a solution, thena dispersed system dosage orm must be developed.

Solubility also dictates the concentration o drug in thedosage orm.5. Drug stability—I the drug has signifcant degrada-

tion problems in solution, then a reeze-dried or othersterile solid dosage orm must be developed. Stability issometimes aected by drug concentration that, in turn,might aect size and type o packaging system used. Forexample, i concentration must be low, due to stabilityand/or solubility limitations, then the size o primarycontainer must be larger, and this might preclude the useo syringes, cartridges, and/or smaller vial sizes. Obvi-ously, stability dictates the expiration date o the productthat, in turn, determines the storage conditions. Storageconditions might dictate choice o container size, ormu-lation components, and type o container. I a productmust be rerigerated, then the container cannot be too

large, and ormulation components must be soluble andstable at colder conditions.

6. Compatibility o drug with potential ormulation ad-ditives and packaging systems—It is well-known thatdrug-excipient incompatibilities requently exist.9 Initialpreormulation screening studies are essential to ensurethat ormulation additives, although possibly solving oneproblem, will not create another. Stabilizers, such as bu-ers and antioxidants, although chemically stabilizing thedrug in one way, may also catalyze other chemical degra-dation reactions. Excipients and certain drugs can orm in-soluble complexes. Impurities in excipients can cause drugdegradation reactions. Peroxide impurities in polymers

may catalyze oxidative degradation reactions with drugs,including proteins, which are oxygen sensitive.

7. The use o silicone to lubricate vial rubber closures,syringe rubber plungers to coat the inner surace o glasssyringes, and cartridges potentially can induce proteinaggregation. Thereore, compatibility studies need to bedesigned to determine the potential or a new biopharma-ceutical drug adversely aected by the presence o siliconeapplied to certain packaging suraces. The increased popu-larity o laminated rubber closures and plungers has beendue to the elimination o the need or applying silicone to

these materials. Silicone coating is still required or glasssyringes and cartridges, which provide new opportunitiesor the use o plastic syringes with biopharmaceuticalsthat urther minimize the potential or incompatibilitiesbetween biopharmaceuticals and packaging systems.

8. Desired type o packaging—Selection o packaging (i.e.,type, size, shape, color o rubber closure, label, andaluminum cap) is oten based on marketing preerencesand competition. Knowing the type o fnal package earlyin the development process aids the ormulation scientistin being sure the product ormulation will be compatibleand elegant in that packaging system.

Table 26-1 provides steps involved in the ormulation o anew parenteral drug product. This can also be viewed as a list o

questions, o which the answers will acilitate decisions on thefnal ormulation that should be developed.

Table 26-1. m sp iod ouo o

n P Du Poduc

1. Obtai physical properties o active drug substace

a. Structure, molecular weight

b. “Practical” solubility i water at room temperature

c. Eect o pH o solubility

d. Solubility i certai other solvets

e. Uusual solubility properties

. Isoelectric poit or a protei or peptide

g. Hygroscopicity

h. Potetial or water or other solvet lossi. Aggregatio potetial or protei or peptide

2. Obtai chemical properties o active drug substace

a. Must have a ‘validatable’ aalytical method or potecy

ad purity

b. Time or 10% degradatio at room temperature i

aqueous solutio i the pH rage o aticipated use

c. Time or 10% degradatio at 5°C

d. pH stability profle

e. Sesitivity to oxyge

. Sesitivity to light

g. Major routes o degradatio ad degradatio products

3. Iitial ormulatio approaches

a. Kow timelie(s) or drug productb. Kow how drug product will be used i the cliic

i. Sigle dose vs multiple dose

ii. I multiple dose, will preservative aget be part o drug

solutio/powder or part o diluet?

iii. Shel lie goals

iv. Combiatio with other products, diluets

c. From kowledge o solubility ad stability properties ad

iormatio rom aticipated cliical use, ormulate drug

with compoets ad solutio properties kow to be

successul at dealig with these issues, the perorm

accelerated stability studies.





i. High temperature storage

ii. Temperature cyclig

iii. Light ad/or oxyge exposure

iv. For powders, expose to high humidities

d. May eed to perorm several short-term stability studies

as excipiet types ad combiatios are elimiated

e. Selectio o primary cotaier ad closure

i. Be aware o potetial or tubig glass to be subject to

glass delamiatio (glass lamellae); work with glass

supplier to select type o glassii. Most rubber closure ormulatios are coated rubber to

miimize leachables ad do ot require silicoizatio

. Desig ad implemet a iitial mauacturig method o

the product

g. Fialize ormulatio

i. need or toicity adjustig aget

ii. need or atimicrobial preservative

h. Approach to obtai sterile product

i. Termial sterilizatio

ii. Sterile fltratio ad aseptic processig

aDministratiOn

Injections may be classifed in six general categories:

1. Solutions ready or injection2. Dry, soluble products ready to be combined with a sol-

vent just prior to use3. Suspensions ready or injection4. Dry, insoluble products ready to be combined with a

vehicle just prior to use5. Emulsions6. Liquid concentrates ready or dilution prior to

administration

When compared with other dosage orms, injections possessselect advantages. I immediate physiological action is neededrom a drug, it can usually be provided by the intravenous in-

jection o an aqueous solution. Modifcation o the ormulationor another route o injection can be used to slow the onset andprolong the action o the drug. The therapeutic response o a drugis controlled more readily by parenteral administration, sincethe irregularities o intestinal absorption are circumvented. Also,since the drug is administered by a proessionally trained per-son, it confdently can be expected that the dose is accuratelyadministered. Drugs can be administered parenterally, when theycannot be given orally, due to the unconscious or uncooperativestate o the patient or due to inactivation or lack o absorption inthe intestinal tract. Among the disadvantages o this dosage ormare the requirement o asepsis at administration, the risk o tissuetoxicity rom local irritation, the real or psychological pain ac-tor, and the difculty in correcting an error, should one be made.In the latter situation, unless a direct pharmacological antagonistis immediately available, correction o an error may be impos-

sible. One other disadvantage is that daily or requent administra-tion pose difculties, as patients must either visit a proessionallytrained person or learn to sel-inject. However, the advent o home health care as an alternative to extended institutional careand availability o new medications rom biotechnology to treatchronic diseases have mandated the development o programs ortraining lay persons to administer these dosage orms.

Parenteral COmbinatiOns

Most dosage orms, when released to the marketplace by themanuacturer, are consumed by the patient without any sig-nifcant manipulation o the product. For example, tablets and

capsules are ingested in the same orm they were when releaseby the manuacturer. For many parenteral drug products, this not the case. For example, products in vials must be withdrawinto a syringe prior to injection and oten combined with otheproducts in inusion solutions prior to administration. Freezdried products, frst, have to be reconstituted with a specifor non-specifc diluent prior to being withdrawn rom the viaSpecifcally, it is common practice or a physician to order thaddition o a small-volume therapeutic injection (SVI), such aan antibiotic, to large-volume injections (LVIs), such as 100mL o 0.9% sodium chloride solution, to avoid the discomor

or the patient, o a separate injection. Certain aqueous vehiclare recognized ofcially, due to their valid use in parenteralOten, they are used as isotonic vehicles to which a drug mabe added at the time o administration. The additional osmoteect o the drug may not be enough to produce any discomowhen administered. These vehicles include Sodium ChloridInjection, Ringer’s Injection, Dextrose Injection, Dextrose anSodium Chloride Injection, and Lactated Ringer’s Injection.

Although the pharmacist is the most qualifed health proesional to be responsible or preparing such combinations, as clearly stated in the hospital accreditation manual o the JoinCommission on Accreditation o Healthcare Organizations,interactions among the combined products can be troublesomeven or the pharmacist. In act, incompatibilities can occuand cause inactivation o one or more ingredients or other un

desired reactions. Patient deaths have been reported rom thprecipitate ormed by two incompatible ingredients. In sominstances, incompatibilities are visible as precipitation or colochange, but, in other instances, there may be no visible eect

The many potential combinations present a complex sitution even or the pharmacist. To aid in making decisions concerning potential problems, a valuable compilation o relevandata has been assembled by Trissel14 and is updated regularlFurther, the advent o computerized data storage and retrievsystems has provided a means to organize and gain rapid accesto such inormation. (Further inormation on this subject mabe ound in Chapter 27—Pharmaceutical Compounding – US<797> Sterile Preparations.)

As studies have been undertaken and more inormation hbeen gained, it has been shown that knowledge o variabactors, such as pH and the ionic character o the active con

stituents, aids substantially in understanding and predicting ptential incompatibilities. Kinetic studies o reaction rates mabe used to describe or predict the extent o degradation. Ultmately, a thorough study should be undertaken o each therpeutic agent in combination with other drugs and IV uids, noonly o generic, but also o commercial preparations, rom thphysical, chemical, and therapeutic aspects.

Ideally, no parenteral combination should be administereunless it has been studied thoroughly to determine its eect othe therapeutic value and saety o the combination. Howevesuch an ideal situation may not exist. Nevertheless, it is the rsponsibility o the pharmacist to be as amiliar as possible witthe physical, chemical, and therapeutic aspects o parentercombinations and to exercise the best possible judgment ato whether or not the specifc combination extemporaneousprescribed is suitable or use in a patient.

general COnsiDeratiOns

An inherent requirement or parenteral preparations is ththey be o the very best quality and provide the maximum saty or the patient. Constant adherence to high moral and proessional ethics on the part o the responsible persons is movital to achieving the desired quality in the products prepared

tyPes O PrOCesses

The preparation o parenteral products may be categorized asmall-scale dispensing, usually one unit at a time, or large-scamanuacturing in which hundreds o thousands o units ma





constitute one lot o product. The ormer category illustratesthe type o processing done in early clinical phase manuactur-ing or in institutions, such as hospital pharmacies. The lattercategory is typical o the processing done in the later clinicalphase and commercial manuacturing in the pharmaceuticalindustry. Wherever they are made, parenteral products must besubjected to the same basic practices o GMPs and good asepticprocessing essential or the preparation o a sae and eectivesterile product o highest quality, however, the methods usedmust be modifed appropriately or the scale o operation.

The small-scale preparation and dispensing o parenteral

products might use sterile components in their preparation.Thereore, the overall process ocuses on maintaining, ratherthan achieving, sterility in the process steps. In the hospitalsetting, the fnal product might have a shel lie measured inhours. However, the extensive movement o patients out o the hospital to home care has modifed hospital dispensingo parenteral products, wherein multiple units are made or agiven patient and a shel lie o 30 days or more is required.Such products are sometimes made in hospital pharmacies,but increasingly in centers set up to provide this service. A discussion o such processing can be ound in the USP generalchapter <1206>.

This chapter emphasizes the preparation o parenteralproducts rom non-sterile components in the highly techno-logically advanced plants o the pharmaceutical industry, us-

ing cGMP principles. In the pursuit o cGMP, considerationshould be given to:

1. Ensuring that the personnel responsible or assigned du-ties are capable and qualifed to perorm them.

2. Ensuring that ingredients used in compounding theproduct have the required identity, quality, and purity.

3. Validating critical processes to be sure the equipmentused and the processes ollowed ensure that the fnishedproduct hase the qualities expected.

4. Maintaining a production environment suitable or per-orming the critical processes required, addressing suchmatters as orderliness, cleanliness, asepsis, and avoid-ance o cross contamination.

5. Confrming, through adequate quality-control proce-dures, that the fnished products have the required

potency, purity, and quality.6. Establishing, through appropriate stability evaluation,

that the drug products retain their intended potency,purity, and quality, until the established expiration date.

7. Ensuring that processes are always carried out in accordwith established, written procedures.

8. Providing adequate conditions and procedures or theprevention o mix-ups.

9. Establishing adequate procedures, with supporting docu-mentation, or investigating and correcting ailures orproblems in production or quality control.

10. Providing adequate separation o quality-control respon-sibilities rom those o production to ensure indepen-dent decision making.

The pursuit o cGMP is an ongoing eort that must ex

with new technological developments and new understand-ing o existing principles. Due to the extreme importance o quality in health care o the public, US Congress has giventhe responsibility o regulatory scrutiny over the manuac-ture and distribution o drug products to the FDA. Thereore,the operations o the pharmaceutical industry are subject tothe oversight o the FDA and, with respect to manuacturingpractices, to the application o the cGMPs. (These regulationsare discussed more ully in Chapter 3—Quality Assurance andControl.)

In concert with the pursuit o cGMPs, the pharmaceuticalindustry has shown initiative and innovation in the extensive

technological development and improvement in quality, saety,and eectiveness o parenteral dosage orms in recent years.Examples include developments in:

• modular acility design and construction—smaller rooms,easier to clean, sanitize, and maintain;

• application o disposable technologies or compounding,mixing, and flling—reduce potential or cross-contamination;

• closure cleaning, siliconization (i applicable), and steril-ization—all-in-one systems or rubber closures;

• sterilization technologies—well-defned sterilizationvalidation principles, multiple approaches to sterilizationcycles;

• flling technologies—greater speed, precision, and han-dling o viscous solutions;

• aseptic processing technology, including barrier isolatortechnology and restricted access barrier systems;

• reeze-drying technologies–automated loading and unload-ing, advances in process monitoring;

• control o particulate matter—greater diligence in clean-ing methodologies, in-coming inspections, more experi-ence with sources, causes, and minimization o particu-late matter in acilities, on equipment and packaging, andpersonnel practices; and

• Automation—weight checking, inspection technologies,

labeling and fnishing operations.

general manUaCtUring PrOCess

The preparation o a parenteral product may encompass ourgeneral areas:

1. Procurement and accumulation o all components in awarehouse area, until released to manuacturing;

2. Processing the dosage orm in appropriately designed andoperated acilities;

3. Packaging and labeling in a quarantine area, to en-sure integrity and completion o the product; and

4. Controlling the quality o the product throughout theprocess.

Procurement encompasses selecting and testing accord-ing to specifcations o the raw-material ingredients and thecontainers and closures or the primary and secondary pack-ages. Microbiological purity, in the orm o bioburden andendotoxin levels, has become standard requirements or raw materials.

Processing includes cleaning containers and equipment tovalidated specifcations, compounding the solution (or otherdosage orm), fltering the solution, sanitizing or sterilizing thecontainers and equipment, flling measured quantities o prod-uct into the sterile containers, stoppering (either completely orpartially or products to be reeze-dried), reeze-drying, termi-nal sterilization (i possible), and fnal sealing o the fnal pri-mary container.

Packaging normally consists o the labeling and cartoning o flled and sealed primary containers. Control o quality begins

with the incoming supplies, being sure that specifcations aremet. Careul control o labels is vitally important, as errors inlabeling can be dangerous or the consumer. Each step o theprocess involves checks and tests to ensure the required speci-fcations at the respective step are being met. Labeling and fnalpackaging operations are becoming more automated.

The quality control unit is responsible or reviewing thebatch history and perorming the release testing required toclear the product or shipment to users. A common FDA cita-tion or potential violation o cGMP is the lack o oversight bythe quality control unit in batch testing and review and ap-proval o results.





COmPOnents

Components o parenteral products include the active ingre-dient, ormulation additives, vehicle(s), and primary containerand closure. Establishing specifcations to ensure the qualityo each o these components o an injection is essential. Sec-ondary packaging is relevant more to marketing considerations,although some drug products might rely on secondary pack-aging or stability considerations, such as added protectionrom light exposure or light-sensitive drugs and antimicrobial

preservatives.The most stringent chemical-purity requirements will nor-mally be encountered with aqueous solutions, particularly i theproduct is sterilized at an elevated temperature where reactionrates will be accelerated greatly. Dry preparations pose relative-ly ew reaction problems but may require defnitive physicalspecifcations or ingredients that must have certain solution ordispersion characteristics when a vehicle is added.

Containers and closures are in prolonged, intimate contactwith the product and may release substances into, or removeingredients rom, the product. Rubber closures are especiallyproblematic (sorption, leachables, air and moisture transmis-sion properties), i not properly evaluated or compatibilitywith the fnal product. Assessment and selection o contain-ers and closures are essential or fnal product ormulation,to ensure the product retains its purity, potency, and quality

during the intimate contact with the container throughout itsshel lie. Administration devices (e.g., syringes, tubing, transersets) that come in contact with the product should be assessedand selected with the same care as are containers and closures,even though the contact period is usually brie.

water Or injeCtiOn (wi)

PreParatiOn

The source water can be expected to be contaminated withnatural suspended mineral and organic substances, dissolvedmineral salts, colloidal material, viable bacteria, bacterial en-dotoxins, industrial or agricultural chemicals, and other par-ticulate matter. The degree o contamination varies with thesource and will be markedly dierent, whether obtained rom awell or rom surace sources, such as a stream or lake. Hence,the source water must be pretreated by one or a combinationo the ollowing treatments: chemical sotening, fltration, de-ionization, carbon adsorption, or reverse osmosis purifcation.Figure 26-1 shows a schematic o a typical process used to con-vert potable water to Water or Injection.

Water or Injection can be prepared by distillation or by membrane technologies (i.e., reverse osmosis or ultrafltration). ThEP ( European Pharmacopeia) only permits distillation as thprocess or producing WFI. The USP and JP ( Japanese Pharm

copeia) allow all these technologies to be applied.Distillation is a process o converting water rom a liquid t

its gaseous orm (steam). Since steam is pure gaseous water, aother contaminants in the eedwater are removed. A conventioal still consists o a boiler (evaporator), containing eed wat(distilland); a source o heat to vaporize the water in the evaprator; a headspace above the level o distilland, with condensin

suraces or reuxing the vapor, thereby returning nonvolatiimpurities to the distilland; a means or eliminating volatile impurities (demister/separation device) beore the hot water vapois condensed; and a condenser or removing the heat o vapoization, thereby converting the water vapor to a liquid distillate

The specifc construction eatures o a still and the procespecifcations have a marked eect on the quality o distillatobtained rom a still. Several actors must be considered in slecting a still to produce WFI:

1. The quality o the eed water will aect the quality o thdistillate. For example, chlorine in water, especially, cancause or exacerbate corrosion in distillation units, andsilica causes scaling within. Controlling the quality o theed water is essential or meeting the required specifca

tions or the distillate.2. The size o the evaporator will aect the efciency. Itshould be large enough to provide a low vapor velocity,thus, reducing the entrainment o the distilland either aa flm on vapor bubbles or as separate droplets.

3. The baes (condensing suraces) determine theeectiveness o reuxing. They should be designed orefcient removal o the entrainment at optimal vaporvelocity, collecting and returning the heavier dropletscontaminated with the distilland.

4. Redissolving volatile impurities in the distillatereduces its purity. Thereore, they should be separatedefciently rom the hot water vapor and eliminated byaspirating them to the drain or venting them to theatmosphere.

5. Contamination o the vapor and distillate rom the metal

parts o the still can occur. Present standards or high-pu-rity stills are that all parts contacted by the vapor or distillate should be constructed o metal coated with pure tin,304 or 316 stainless-steel, or chemically resistant glass.

The design eatures o a still also inuence its efciency operation, relative reedom rom maintenance problems, or extent o automatic operation. Stills may be constructed o varing size, rated according to the volume o distillate that cabe produced per hour o operation under optimum conditionOnly stills designed to produce high-purity water may be considered or use in the production o WFI. Conventional commercial stills designed or the production o high-purity wateare available rom several suppliers.

There are two basic types o WFI distillation units—the vapocompression still and the multiple eect still.

Copo Do

The vapor-compression still, primarily designed or the prduction o large volumes o high-purity distillate with low consumption o energy and water, is illustrated diagrammatically Figure 26-2. To start, the eed water is heated rom an externsource in the evaporator to boiling. The vapor produced in thtubes is separated rom the entrained distilland in the separatand conveyed to a compressor that compresses the vapor anraises its temperature to approximately 107°C. It then ows tthe steam chest, where it condenses on the outer suraces o thtubes containing the distilland; the vapor is, thus, condense

Sand Filter(s)

Dechlorinator

(Sodium metasulfite

or Carbon banks)

Multiple Effect Still

Polisher

(Secondary softener)

Primary Softener (Cation

softener, resin banks)

Clean Steam Generator

Storage Tank

Hot Loop

Reverse Osmosis System

(Several stages)

Cool Loop

City water

u 26-1. A schematic o a typical process used to convert potablewater to Water or Injection.





and drawn o as a distillate, while giving up its heat to bring thedistilland in the tubes to the boiling point. Vapor-compression

stills are available in capacities rom 50 to 2800 gal/hr.

mup-ec s

The multiple-eect still is also designed to conserve energy and

water usage. In principle, it is simply a series o single-eectstills or columns running at diering pressures where phasechanges o water take place. A series o up to seven eects maybe used, with the frst eect operated at the highest pressureand the last eect at atmospheric pressure. Figure 26-3 shows aschematic drawing o a multiple-eect still. Steam rom an ex-ternal source is used in the frst eect to generate steam underpressure rom eed water; it is used as the power source to drivethe second eect. The steam used to drive the second eectcondenses as it gives up its heat o vaporization and orms adistillate. This process continues until the last eect, when thesteam is at atmospheric pressure and must be condensed in aheat exchanger.

The capacity o a multiple-eect still can be increased byadding eects. The quantity o the distillate will also be aectedby the inlet steam pressure; thus, a 600-gal/hr unit designed

to operate at 115 psig steam pressure could be run at approxi-mately 55 psig and would deliver about 400 gal/hr. These stillshave no moving parts and operate quietly. They are available incapacities rom about 50 to 7000 gal/hr.

r Oo (rO)

As the name suggests, the natural process o selective perme-ation o molecules through a semipermeable membrane sepa-rating two aqueous solutions o dierent concentrations isreversed. Pressure, usually between 200 and 400 psig, is appliedto overcome osmotic pressure and orce pure water to perme-ate through the membrane. Membranes, usually composed o

cellulose esters or polyamides, are selected to provide an ef-cient rejection o contaminant molecules in raw water. The mol-ecules most difcult to remove are small inorganic molecules,such as sodium chloride. Passage through two membranes inseries is sometimes used to increase the efciency o removal o these small molecules and decrease the risk o structural ailure

o a membrane to remove other contaminants, such as bacteriaand pyrogens.Several WFI installations utilize both RO and distillation sys-

tems or generation o the highest quality water. Since eedwa-ter to distillation units can be heavily contaminated and, thus,aect the operation o the still, water is frst run through ROunits to eliminate contaminants. (For additional inormation,see the book by Collentro.)15

Whichever system is used or the preparation o WFI, valida-tion is required to be sure that the system, consistently andreliably, produces the chemical, physical, and microbiologicalquality o water required. Such validation should start withthe determined characteristics o the source water and in-clude the pretreatment, production, storage, and distributionsystems. All o these systems together, including their properoperation and maintenance, determine the ultimate quality o

the WFI.

so d Duo

The rate o production o WFI is not sufcient to meet process-ing demands; thereore, it is collected in a holding tank or sub-sequent use. In large operations, the holding tanks may havea capacity o several thousand gallons and be a part o a con-tinuously operating system. In such instances, the USP requiresthat the WFI be held at a temperature too high or microbialgrowth, normally a constant 80°C.

The USP also permits the WFI to be stored at room tempera-ture but or a maximum o 24 hours. Under such conditions,

u 26-2. Vapor compressor still.

COMPRESSOR

DRIVEN BY EITHER ELECTRIC

MOTOR OR DIESEL ENGINE

COMPRESSED STEAM

APPROX T = 224°F

VENT

OVERFLOW APPROX. T = 90°F.

FEED APPROX T = 60°F

CONDENSATE APPROX. T = 74°F.

NOTE: SUPPLEMENTAL HEAT

ELECTRIC UNITS-ELECTRIC HEATERS

DIESEL UNITS-ENGINE COOLING &

EXHAUST SYSTEMS

DOUBLE PIPE HEAT EXCHANGER

CONDENSATE

FEED

OVERFLOW

OVERFLOW

APPROX

T=224ºF

VENT

ORIFICE

VAPOR SEPARATOR

FEED

APPROXT=200ºF

STEAM 212ºF





u 26-3. Multiple-eect water or injection distillation. Schematic (A) and (B) a space saving and energy efcient combinatiostill and steam generator capable o delivering 750kg/hr (1650lb/hr) o pharmaceutical grade steam and 2200 liters/hr (580 gal/ho Water For Injection. (Courtesy o Getinge.)

P l an t

S t e am

Condensate

Return

Drain

(Blowdown)

A

Cooling

Water

C o ol i n g

W a t er

F e e d

W a t er

VENT

V E NT

Dump

W F I

T C

the WFI is collected as a batch or a particular use with anyunused water discarded within 24 hours. Such a system re-quires requent sanitization to minimize the risk o viable mi-croorganisms being present. The stainless-steel storage tanksin such systems are usually connected to a welded stainless-steel distribution loop, supplying the various use sites with acontinuously circulating water supply. The tank is providedwith a hydrophobic membrane vent flter capable o exclud-ing bacteria and nonviable particulate matter. Such a ventflter is necessary to permit changes in pressure during fll-ing and emptying. The construction material or the tank and

connecting lines is usually electropolished 316L stainless ste

with welded pipe. The tanks also may be lined with glass or

coating o pure tin. Such systems are very careully designe

and constructed and oten constitute the most costly install

tion within the plant.

When the water cannot be used at 80°C, heat exchange

must be installed to reduce the temperature at the point o us

Bacterial retentive flters should not be installed in such sy

tems, due to the risk o bacterial buildup on the flters and th

consequent release o pyrogenic substances.





Pu

Although certain purity requirements have been alluded to, theUSP and EP monographs provide the ofcial standards o purityor WFI and Sterile Water or Injection (SWFI).

The chemical and physical standards or WFI have changed inthe past ew years. The only physical/chemical tests remainingare the new total organic carbon (TOC), with a limit o 500 ppb(0.5 mg/L), and conductivity , with a limit o 1.3 μS/cm at 25°Cor 1.1 μS/cm at 20°C. The ormer is an instrumental method ca-pable o detecting all organic carbon present, and the latter is a

three-tiered instrumental test measuring the conductivity con-tributed by ionized particles (in microSiemens or micromhos)relative to pH. Since conductivity is integrally related to pH, thepH requirement o 5 to 7 in previous revisions has been eliminat-ed. The TOC and conductivity specifcations are now consideredadequate minimal predictors o the chemical/physical purity o WFI. However, the wet chemistry tests are still used when WFI ispackaged or commercial distribution and or SWFI.

Biological requirements continue to be, or WFI, not morethan 10 colony-orming units (CFUs)/100 mL and less than 0.25USP endotoxin units/mL. The SWFI requirements dier in that,since it is a fnal product, it must pass the USP Sterility Test.

WFI and SWFI may not contain added substances. Bacterio-static Water or Injection (BWFI) may contain one or more suit-able antimicrobial agents in containers o 30 mL or less. Thisrestriction is designed to prevent the administration o a large

quantity o a bacteriostatic agent that would probably be toxicin the accumulated amount o a large volume o solution, eventhough the concentration was low.

The USP also provides monographs giving the specifcationsor Sterile Water or Inhalation and Sterile Water or Irrigation.The USP should be consulted or the minor dierences betweenthese specifcations and those or SWFI.

COntainers anD ClOsUres

Injectable ormulations are packaged into containers made o glass or plastic. Container systems include ampoules, vials, sy-ringes, cartridges, bottles, and bags (Fig. 26-4).

Ampoules are all glass, whereas bags are all plastic. The othercontainers can be composed o glass or plastic and must include

rubber materials, such as rubber stoppers or vials and bottlesand rubber plungers and rubber seals or syringes and cartridg-es. Irrigation solutions are packaged in glass bottles with alumi-num screw caps.

Table 26-2 provides a generalized comparison o the threecompatibility properties—leaching, permeation, and adsorp-tion—o container materials most likely involved in the or-mulation o aqueous parenterals. Further, the integrity o thecontainer/closure system depends on several characteristics,including container opening fnish, closure modulus, durom-eter and compression set, and aluminum seal application orce.

(Container-closure integrity testing is discussed in the Quality Assurance and Control section.)

COntainer tyPes

glass

Glass is employed as the container material o choice or mostSVIs. It is composed, principally, o silicon dioxide, with varyingamounts o other oxides, such as sodium, potassium, calcium,magnesium, aluminum, boron, and iron. The basic structuralnetwork o glass is ormed by the silicon oxide tetrahedron. Bo-ric oxide will enter into this structure, but most o the otheroxides do not. The latter are only loosely bound, are presentin the network interstices, and are relatively ree to migrate.These migratory oxides may be leached into a solution in con-

tact with the glass, particularly during the increased reactivityo thermal sterilization. The oxides dissolved may hydrolyze toraise the pH o the solution and catalyze or enter into reactions. Additionally, some glass compounds will be attacked by solu-tions and, in time, dislodge glass akes into the solution. Suchoccurrences can be minimized by the proper selection o theglass composition.

tp

The USP provides a classifcation o glass:

• Type I, a borosilicate glass;• Type II, a soda-lime treated glass;• Type III, a soda-lime glass; and• NP, a soda-lime glass not suitable or containers or

parenterals.

Type I glass is composed, principally, o silicon dioxide (~81%)and boric oxide (~13%), with low levels o the non-network-orming oxides, such as sodium and aluminum oxides. It is achemically resistant glass (low leachability), also having a low thermal coefcient o expansion (CoE) ( 32.5 x 10-7 cm/cm-°Cor 33 expansion glass; 51.0 x 10-7 cm/cm-°C or 51 expansionglass). In comparison, soda-lime glass has a thermal CoE o ex-pansion o 8.36 x 10-5 /cm/cm-°C. The lower the thermal CoE,the more dimensionally stable the glass against thermal expan-sion stress that can result in cracking.

Types II and III glass compounds are composed o relativelyhigh proportions o sodium oxide (~14%) and calcium oxide(~8%). This makes the glass chemically less resistant. Bothtypes melt at a lower temperature, are easier to mold into vari-

ous shapes, and have a higher thermal coefcient o expansion. Although there is no one standard ormulation or glass amongmanuacturers o these USP type categories, Type II glass has alower concentration o the migratory oxides than Type III. Inaddition, Type II has been treated under controlled temperatureand humidity conditions, with sulur dioxide or other dealkaliz-ers to neutralize the interior surace o the container. Althoughit remains intact, this surace increases substantially the chem-ical resistance o the glass. However, repeated exposures to ster-ilization and alkaline detergents break down this dealkalizedsurace and expose the underlying soda-lime compound.

The glass types are determined rom the results o two USPtests: the Powdered Glass Test and the Water Attack Test. A

u 26-4. Various types o packaging or parenterals. (Courtesyo Gerresheimer.)





proposal to revise USP <660> Containers-Glass had been pub-lished ( Pharmacopeial Forum, 37(2), March-April, 2011) inwhich the USP would adopt the EP’s methodology or the glassgrains test to replace the USP powdered glass test and the waterattack test would be deleted. The latter is used only or TypeII glass and is perormed on the whole container, due to thedealkalized surace; the ormer is perormed on powdered glass,which exposes internal suraces o the glass compound. Theresults are based on the amount o alkali titrated by 0.02 N

suluric acid, ater an autoclaving cycle with the glass sample incontact with a high-purity distilled water. Thus, the PowderedGlass Test challenges the leaching potential o the interiorstructure o the glass, whereas the Water Attack Test challengesonly the intact surace o the container.

Selecting the appropriate glass composition is a criticalacet o determining the overall specifcations or each paren-teral ormulation. Glass can be the source/cause o leachables/ extractables, particulates (glass delamination or glass lamellaeormation), adsorption o ormulation components, especiallyproteins, and cracks/scratches.

Leachables/Extractables—I the product is sensitive to thepresence o ions, such as boron, sodium, potassium, calcium,iron, and magnesium, great care must be taken in selectingthe appropriate glass container, as these ions may leach romthe glass container and interact with the product, reducing

chemical stability, inducing ormation o particulate, or al-tering pH o solution. Drug ormulations and thermal historycan impact dissolution rates o glass and induce the leachingo signifcant quantities o glass metals. The presence o or-mulation components that can act as metal chelating agents,such as EDTA and citrate, is o special concern. Formulationstudies involving accelerated aging (increased temperatures)should monitor changes in solution pH, metal content, andparticulate ormation, in addition to drug product stability(purity and potency). Leachables rom the glass barrel, suchas tungsten (used or the ormation o the barrel) and silicone(used or lubrication o the syringe), were shown to have sig-nifcant impact on the protein stability.16

The ollowing rules apply with respect to glass leachables:

• Relatively low levels o leachables at pH 4-8.• Relatively high levels o leachables at pH > 9.• Major extractables are silicon and sodium.• Minor extractables include potassium, barium, calcium,

and aluminum.• Trace extractables include iron, magnesium, and zinc.• Treated glass gives less extractables, i pH < 8.

Delamination—Delamination, or glass particulate ormtion, is caused by chemical attack on the glass matrix by thormulation solution, resulting in weakening o the glass aneventual dislodgement o akes rom the glass surace.17 Theragments can be subvisible in size and, thus, difcult to detect. Delamination is o particular concern in tubing vials, ansusceptibility may be driven by many o the same heat historactors that inuence alkali leaching potential (as measureby compendial methods as a pH shit), although measures treduce alkali leaching (ammonium sulate treatment) may bcompletely ineective in reducing delamination susceptibility

Certain components or characteristics o the pharmaceuticproduct ormulation may enhance the potential or delamintion o the product container. Formulations with elevated p(particularly >8), high sodium chloride content, or containin

specifc buer components, known to attack or solubilize components, o the glass matrix (phosphate, citrate, tartrate, EDTAare o potential concern. In some cases, delamination may breduced or eliminated by careul control o process parameteduring the glass orming processes; lower heat levels during thconversion process may be critical. Ammonium sulate-treaed glass containers are also known to be more susceptible delamination.

Although compendial chemical resistance testing may bpredictive o delamination potential, in some cases, experiencindicates that additional testing with the actual ormulation oa surrogate is required to properly evaluate container selectioFor example, a product that undergoes terminal sterilizatio

Table 26-2. Cop Cop Pop o Co m

Leaching PermeationAdsorption (Selective)ExtentaExtenta Potential Leachables Extenta Potential Agents

Glass

Borosilicate 1 Alkalie earth ad heavy

metal oxides0 n/A 2

Soda-lime 5 Alkalie earth ad heavy

metal oxides0 n/A 2

Plastic polymersLow desity 2 Plasticizers, atioxidats 5 Gases, water vapor, other

molecules2

High desity 1 Atioxidats 3 Gases, water vapor, other

molecules2

PVC 4 HCl, especially plasticizers,

atioxidats, other stabilizers5 Gases, especially water

vapor ad other molecules2

Polyolefs 2 Atioxidats 2 Gases, water vapor 2

Polypropylee 2 Atioxidats, lubricats 4 Gases, water vapor 1

Rubber polymers

natural ad

related sythetic5 Heavy metal salts, lubricats,

reducig agets3 Gases, water vapor 3

Butyl 3 Heavy metal salts, lubricats,

reducig agets1 Gases, water vapor 2

Silicoe 2 Miimal 5 Gases, water vapor 1

a Approximate scale o 1 to 5, with 1 as the lowest.





could be evaluated by multiple sterilization cycles in the ormu-lation matrix, ollowed by fltration and microscopic examina-tion o the flters or subvisible particles o delaminated glass.For sterile-fll applications, it is recommended that the glasscontainers be flled with ormulation placebo (all componentsexcept the unstable API) at the pH release limit(s) or the prod-uct and be challenged with a single autoclave cycle or an ac-celerated aging study at 55°C or at least 4 weeks, ollowed byfltration and microscopic examination or glass particles.

Adsorption— Adsorption o drug to solution contact suracesand consequent loss o potency o delivered solution is a primary

concern o container/solution compatibility and must be rigor-ously and ormally evaluated during solution/container evaluationand stability studies. Glass containers are airly inert suraces, ormost small drug products at relatively high concentrations, butpose a higher risk or therapeutic proteins and other smaller drugproducts ormulated at low concentrations. Since adsorption is asurace phenomenon, increasing the surace area to volume ratioincreases the risk o losses due to adsorption. Thus, small volumeproducts carry higher risk or loss o potency due to adsorptionand should be careully evaluated or drug loss.18

Cracks and Scratches—Small cracks and scratches on glasscontainers can best be minimized by implementation o qualityagreements between parenteral product manuacturers and glasscontainer manuacturers. Not only does the glass container man-uacturer need strict control procedures to minimize cracks and

scratches rom the time the container is ormed until it reachesthe fnished product manuacturer, but there also needs to behigh quality, 100% inspection practices by both glass and fnalproduct manuacturers. Also, local quality inspection proceduresand practices need to have clearly understood defnitions and alibrary o examples or what is defned as a crack and scratch.Cracks are considered unacceptable, whereas scratches aremore o an esthetic indication o product elegance.

Type I glass will be suitable or all products, although sulurdioxide treatment is sometimes used or even greater resistanceto glass leachables. Because cost must be considered, one o the other, less-expensive types may be acceptable. Type II glassmay be suitable, or example, or a solution that is buered,has a pH below 7, or is not reactive with the glass. Type IIIglass is usually suitable or anhydrous liquids or dry substanc-es. However, some manuacturer-to-manuacturer variation in

glass composition should be anticipated within each glass type.Thereore, or highly chemically sensitive parenteral ormula-tions, it may be necessary to speciy both USP Type and specifcmanuacturer.

Schott developed a technology, called Plasma Impulse Chem-ical Vapor Deposition (PECVD), that coats the inner surace o Type I glass vials with an ultrathin flm o silicon dioxide.19 Thisflm orms a highly efcient diusion barrier that practicallyeliminates glass leachables. Such treated glass is especially use-ul or drug products having high pH values, ormulations withcomplexing agents, or products showing high sensitivity to pHshits.

Pc Ccc

Commercially available containers vary in size rom 0.5 to 1000mL. Sizes up to 100 mL may be obtained as ampoules and vials,

and larger sizes as bottles. The latter are used or intravenousand irrigating solutions. Smaller sizes are also available as syring-es and cartridges. Ampoules, syringes, and cartridges are drawnrom glass tubing. The smaller vials may be made by moldingor rom tubing. Larger vials and bottles are made only by mold-ing. Containers made by drawing tubing are optically clearer andhave a thinner wall than molded containers (Fig. 26-4). Com-pared to molded glass, tubing glass also has better wall and fnishdimensional consistency and no seams, is easier to label, weighsless, acilitates inspection, and has lower tooling costs. Tubingglass is preerable to molded glass or reeze-dried products, dueto more efcient heat transer rom the shel into the product. Molded containers are uniorm in external dimensions, stronger,

and heavier. Also, molded glass is not as susceptible to leachablesand delamination, because the glass ormation temperatures tovaporize and condense the alkali components o the glass arenot as high as or tubing container manuacture.20 Easy-openingampoules that permit the user to break o the tip at the neckconstriction, without the use o a fle, are weakened at the neck,by scoring or applying a ceramic paint with a dierent coefciento thermal expansion. An example o a modifcation o containerdesign to meet a particular need is the double-chambered vial,designed to contain a reeze-dried product in the lower, and sol-vent in the upper chamber. Other examples are wide-mouth am-

poules with at or rounded bottoms to acilitate flling with drymaterials or suspensions and various modifcations o the car-tridge or use with disposable dosage units.

Glass containers must be strong enough to withstand thephysical shocks o handling and shipping and the pressure di-erentials that develop, particularly during the autoclave ster-ilization cycle. They must be able to withstand the thermalshock resulting rom large temperature changes during process-ing, or example, when the hot bottle and contents are exposedto room air at the end o the sterilization cycle. Thereore, aglass with a low coefcient o thermal expansion is necessary.The container must also be transparent to permit inspection o the contents.

Preparations that are light-sensitive must be protected, byplacing them in amber glass containers or by enclosing int

glass containers in opaque cartons labeled to remain on thecontainer during the period o use. It should be noted that theamber color o the glass is imparted by the incorporation o po-tentially leachable heavy metals, mostly iron and manganese,which may act as catalysts or oxidative degradation reactions.Silicone coatings are sometimes applied to containers to pro-duce a hydrophobic surace, or example, as a means o reduc-ing the riction o a rubber-tip o a syringe plunger.

The size o single-dose containers is limited to 1000 mL bythe USP, and multiple-dose containers to 30 mL, unless statedotherwise in a particular monograph. Multiple-dose vials arelimited in size to reduce the number o punctures or with-drawing doses and the accompanying risk o contamination o the contents. As the name implies, single-dose containers areopened or penetrated with aseptic care, and the contents usedat one time. These may range in size rom 1000-mL bottles to

1-mL or less ampoules, vials, or syringes. The integrity o thecontainer is destroyed when opened, so that the container can-not be closed and reused.

A multiple-dose container is designed so that more than onedose can be withdrawn at dierent times, the container main-taining a seal between uses. It should be evident that, with ullaseptic precautions, including sterile syringe and needle orwithdrawing the dose and disinection o the exposed suraceo the closure, there is still a substantial risk o introducingcontaminating micro-organisms and viruses into the contentso the vial. Due to this risk, the USP requires that all multi-ple-dose vials contain an antimicrobial agent or be inherentlyantimicrobial, as determined by the USP Antimicrobial Preser-vatives-Eectiveness tests. There are no comparable antiviraleectiveness tests, nor are antiviral agents available or suchuse. In spite o the advantageous exibility o dosage provided

by multiple-dose vials, single-dose, disposable container unitsprovide the clear advantage o greater sterility assurance andpatient saety.

Due to concerns or user saety and glass particulate matteroccurring when glass is broken, glass sealed ampoules are nolonger glass containers o choice or new SVIs in the UnitedStates.

rUbber ClOsUres

To permit introduction o a needle rom a hypodermic syringeinto a multiple-dose vial and provide or resealing as soonas the needle is withdrawn, each vial is sealed with a rubber





closure held in place by an aluminum cap (Fig. 26-5). Thisprinciple is also ollowed or single-dose containers o the car-tridge type, except that there is only a single introduction o the needle to make possible the withdrawal or expulsion o the contents.

Rubber closures are composed o multiple ingredients plasti-cized and mixed together at an elevated temperature on mill-

ing machines. The elastomer primarily used in rubber closures,plungers, and other rubber items used in parenteral packagingand delivery systems is synthetic butyl or halobutyl rubber.Natural rubber is also used, but, i it is natural rubber latex,then the product label must include a warning statement, dueto the potential or allergic reactions rom latex exposure.

The plasticized mixture is placed in molds and vulcanized(cured) under high temperature and pressure. During vulcani-zation the polymer strands are cross-linked by the vulcanizingagent, assisted by the accelerator and activator, so that motionis restricted and the molded closure acquires the elastic, re-silient character required or its use. Ingredients not involvedin the cross-linking reactions remain dispersed within the

compound and, along with the degree o curing, aect the proerties o the fnished closure. Table 26-3 provides examples rubber-closure ingredients.

The physical properties considered in the selection o a paticular ormulation include elasticity, hardness, tendency tragment, and permeability to vapor transer. The elasticity critical in establishing a seal with the lip and neck o a vial oother opening and in resealing ater withdrawal o a hypodemic needle rom a vial closure. The hardness should providfrmness, but not excessive resistance to the insertion o a nedle through the closure, and minimal ragmentation o pieces rubber should occur as the hollow shat o the needle is pushethrough the closure. Although vapor transer occurs to somdegree with all rubber ormulations, appropriate selection ingredients makes it possible to control the degree o perm

ability. Physicochemical and toxicological tests or evaluatinrubber closures are described in section <381> in the USP.

The ingredients dispersed throughout the rubber compounmay be subject to leaching into the product contacting thclosure. These ingredients (Table 26-3) pose potential compaibility interactions with product ingredients, i leached into thproduct solution, and these eects must be evaluated. Furthesome ingredients must be evaluated or potential toxicity.

The example o pure red cell aplasia, an immunogenic reation caused by leachables rom a rubber closure in a erythropoietin preflled syringe ormulation, highlights the criticality appropriate container-closure and the study o such leachabland extractables, even as a unction o stability shel lie.21

To reduce the problem o leachables, laminates have beeapplied to the product contact suraces o closures, with varioupolymers, the most successul being Teon® (DuPont polytetr

uoroethylene [PTFE]) and Flurotec® (West/Daikyo copolymo tetrauoroethylene and ethylene). Polymeric coatings havbeen developed that are claimed to have more integral bindinwith the rubber matrix, however, details o their unction atrade secrets. Although rubber coatings do reduce the potentior extractables/leachables and eliminate the need or appliesilicone treatment, they may have potential disadvantages not owing as easily during high speed flling operations anmay not have the same container-closure integrity as uncoatestoppers with vial openings.

The physical shape o some typical closures may be seen iFigure 26-5. Most o them have a lip and a protruding ange thextends into the neck o the vial or bottle. Many disk closure

u 26-5. Examples o rubber closures or vials and syringes.(Photo Copyright 2011, West Pharmaceutical Services, Inc., Usedwith Permission).

Table 26-3. ep o id oud ru

Cou

Ingredient Examples

Elastomer natural rubber (latex)

Butyl rubber

neopree

Vulcaizig (curig aget) Sulur

Peroxides

Accelerator Zic dibutyldithiocarbamate Activator Zic oxide

Stearic acid

Atioxidat Dilauryl thiodipropioate

Plasticizer/lubricat Parafic oil

Silicoe oil

Fillers Carbo black

Clay

Barium sulate

Pigmets Iorgaic oxides

Carbo black





are being used now, particularly in the high-speed packaging o antibiotics. Slotted closures are used on reeze-dried productsto permit the escape o water vapor, since they are inserted onlypartway into the neck o the vial until completion o the dryingphase o the cycle. Also, the top design o the reeze-dry closureis important to minimize sticking o the closure to underneaththe dryer shel ater stoppering the vial. Stoppers normally havea small protruding circle at the center o the top o the stopper.Gaps provided within the protruding circle minimize the ten-dency o the stopper to stick to the reeze-dryer shel.

The plunger type o rubber is used to seal one end o a syringe

or cartridge. At the time o use, the plunger expels the productby a needle inserted through the closure at the distal end o thepackage. Intravenous solution closures oten have permanentholes or adapters o administration sets; irrigating solution clo-sures are usually designed or pouring.

Rubber closures must be ‘slippery’ to move easily through arubber closure hopper and other stainless steel passages, untilthey are ftted onto the flled vials. Traditionally, rubber materi-als are ‘siliconized’ (silicone oil or emulsion applied onto therubber) to produce such lubrication. However, advances in rub-ber closure technologies have introduced closures that do notrequire siliconization, due to a special polymer coating appliedto the outer surace o the closure. Examples are the Daikyo/ West closures (Flurotec) and the Helvoet (Omniex) closures.

PlastiC

Thermoplastic polymers have been established as packagingmaterials or sterile preparations, such as large-volume paren-terals, ophthalmic solutions, and, increasingly, small- volumeparenterals. For such use to be acceptable, a thorough under-standing o the characteristics, potential problems, and advan-tages or use must be developed. Three principal problem areasexist in using these materials:

1. Permeation o vapors and other molecules in either direc-tion through the wall o the plastic container;

2. Leaching o constituents rom the plastic into the prod-uct; and

3. Sorption (absorption and/or adsorption) o drug mol-ecules or ions on the plastic material.

Permeation, the most extensive problem, may be troublesomeby permitting volatile constituents, water, or specifc drug mol-ecules to migrate through the wall o the container to the outsideand, thereby, be lost. This problem has been resolved, or exam-ple, by the use o an overwrap in the packaging o IV solutions inPVC bags to prevent loss o water during storage. Reverse perme-ation in which oxygen or other molecules may penetrate to theinside o the container and cause oxidative or other degradationo susceptible constituents may also occur. Leaching may be aproblem, when certain constituents in the plastic ormulation,such as plasticizers or antioxidants, migrate into the product.Thus, plastic polymer ormulations should have as ew additivesas possible, an objective characteristically achievable or mostplastics used or parenteral packaging. Sorption is a problem ona selective basis, that is, sorption o a ew drug molecules occurson specifc polymers. For example, sorption o insulin and other

proteins, vitamin A acetate, and wararin sodium has been shownto occur on PVC bags and tubing, when these drugs were presentas additives in IV admixtures. Table 26-2 gives a brie summaryo some o these compatibility relationships.

One o the principle advantages o using plastic packagingmaterials is that they are not breakable, as is glass; also, thereis a substantial weight reduction. The exible bags o polyvinylchloride or select polyolefns, currently in use or large-volumeintravenous uids, have the added advantage that no air inter-change is required; the exible wall simply collapses as the so-lution ows out o the bag.

Most plastic materials have the disadvantage o not beingas clear as glass, and, thereore, inspection o the contents is

impeded. However, recent technologies have overcome this limi-tation, evidenced by plastic resins, such as CZ (polycyclopentane,Daikyo Seiko) and Topas COC (cyclic olefn copolymer, Ticona).In addition, many o these materials soten or melt under theconditions o thermal sterilization. However, careul selection o the plastic used and control o the autoclave cycle has made ther-mal sterilization o some products possible, large-volume inject-ables, in particular. Ethylene oxide or radiation sterilization maybe employed or the empty container with subsequent asepticflling. However, careul evaluation o the residues rom ethyleneoxide or its degradation products and their potential toxic eect

must be undertaken. Investigation is required concerning poten-tial interactions and other problems that may be encounteredwhen a parenteral product is packaged in plastic.

Future trends in primary packaging or parenterals will con-tinue to see signifcant growth in the application o plastic vi-als and syringes and the manuacturing o such packaging byorm- (or blow-) fll-seal technologies. (For urther details, seeChapter 35 (Pharmaceutical Packaging) and the review bookchapter by Vilivalam and DeGrazio.22

neeDles

Historically, stainless steel needles have been used to penetratethe skin and introduce a parenteral product inside the body.The advent o needleless injection systems has obviated theneed or needles or some injections (e.g., vaccines) and is gain-

ing in popularity over the conventional syringe and needle sys-tem. However, needleless injections are more expensive, canstill produce pain on injection, are, potentially, a greater sourceo contamination (and cross-contamination rom incessantuse), and may not be as efcient in dose delivery.

Needles are hollow devices composed o stainless steel orplastic. Needles are available in a wide variety o lengths, sizes,and shapes. Needle lengths range rom ¼ inch to 6 inches. Nee-dle size is reerred to as its gauge (G), or the outside diameter(OD) o the needle shat. Gauge ranges are 11 to 32 G, with thelargest gauge or injection usually being no greater than 16 G.16 G needles have an OD o 0.065 inches (1.65 mm), whereas32 G have an OD o 0.009 inches (0.20 mm). Needle shape in-cludes regular, short bevel, intradermal, and winged. Needleshape is defned by one end o a needle enlarged to orm a hub

with a delivery device, such as a syringe, or other administra-tion device. The other end o the needle is beveled, meaning itorms a sharp tip to maximize ease o insertion.

The route o administration, type o therapy, and whether thepatient is a child or adult dictate the length and size o needleused. Intravenous injections use 1–2 inch 15–25 G needles. In-tramuscular injections use 1–2 inch 19–22 G needles. Subcuta-neous injections use ¼–5/8 inch 24–25 G needles. Needle gaugeor children rarely is larger than 22 G, usually 25–27G. Wingedneedles are used or intermittent heparin therapy. Many dier-ent types o therapies (e.g,. radiology, anesthesia, biopsy, car-diovascular, ophthalmic, transusions, tracheotomy, etc.) havetheir own peculiar types o needle preerences.

Needles are purchased either alone (e.g., Luer-Lok) to be at-tached to syringes, cartridges, and other delivery systems, or, orsyringes, can be part o the syringe set (stake needle). Syringes

with needles may also have needle protectors (or example, seehttp://www.bd.com/vacutainer/ pds/blood_transer_device_with_saetyglide_needle_VS5985.pd) to avoid potential dangerso accidental needle sticks post-administration (or more detailregarding the 2000 Needlestick Saety Act, see http://rwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=106_cong_public_laws&docid=:publ430.106). Such protectors can either be parto the assembly or be assembled during the fnishing process.Needlestick prevention can be manual (shield activated manu-ally by the user, although there is still the risk o accidentalsticking), active (automated needle shielding activated byuser), or passive (automated needle shielding without actionby the user).





PyrOgens (enDOtOxins)

Water and packaging materials are the greatest sources o py-rogens (pyrogenic contamination). Pyrogens are products o metabolism o microorganisms. The most potent pyrogenic sub-stances (endotoxins) are constituents (lipopolysaccharides, LPS)o the cell wall o gram-negative bacteria (e.g., Pseudomonas sp,

Salmonella sp, Escherichia coli). Gram-positive bacteria andungi also produce pyrogens but o lower potency and o dier-ent chemical nature. Gram positive bacteria produce peptidogly-

cans, whereas ungi product β-glucans, both o which can causenon-endotoxin pyrogenic responses. Endotoxins are lipopolysac-charides that exist in high molecular weight aggregate orms.However, the monomer unit o LPS is less than 10,000 daltons,enabling endotoxin to easily pass through sterilizing 0.2 micronflters. The lipid portion o the molecule is responsible or the bi-ological activity. Since endotoxins are the most potent pyrogensand gram-negative bacteria are ubiquitous in the environment,especially water, this discussion ocuses on endotoxins and therisk o their presence as contaminants in sterile products.

Pyrogens, when present in parenteral drug products and injected into patients, can cause ever, chills, pain in the backand legs, and malaise. Although pyrogenic reactions are rarelyatal, they can cause serious discomort and, in the seriouslyill patient, shock-like symptoms that can be atal. The inten-sity o the pyrogenic response and its degree o hazard are

aected by the medical condition o the patient, the potencyo the pyrogen, the amount o the pyrogen, and the route o administration (intrathecal is most hazardous ollowed byintravenous, intramuscular, and subcutaneous). When bacte-rial (exogenous) pyrogens are introduced into the body, LPStargets circulating mononuclear cells (monocytes and macro-phages) that, in turn, produce pro-inammatory cytokines,such as interleukin 2, interleukin 6, and tissue necrosis ac-tor. Besides LPS, gram-negative bacteria also release manypeptides (e.g., exotoxin A, peptidoglycan, and muramuyl pep-tides) that can mimic the activity o LPS and induce cytokinerelease. The Limulus Amebocyte Lysate (LAL) test can onlydetect the presence o LPS. It has been suggested that the Monocyte Activation Test, replace LAL as the ofcial pyrogentest, due to its greater sensitivity to all agents that induce therelease o cytokines that cause ever and a potential cascade

o other adverse physiological eects.23

COntrOl O PyrOgens

It is impractical, i not impossible, to remove pyrogens, oncepresent, without adversely aecting the drug product. There-ore, the emphasis should be on preventing the introduction ordevelopment o pyrogens in all aspects o the compounding andprocessing o the product.

Pyrogens may enter a preparation through any means thatwill introduce living or dead micro-organisms. However, cur-rent technology permits the control o such contamination, andthe presence o pyrogens in a fnished product indicates pro-cessing under inadequately controlled conditions. It also shouldbe noted that time or microbial growth to occur increases therisk or elevated levels o pyrogens. Thereore, compounding

and manuacturing processes should be carried out as expedi-tiously as possible, preerably planning completion o the pro-cess, including sterilization, within the maximum allowed time,according to process validation studies. Aseptic processingguidelines require establishment o time limitations throughoutprocessing or the primary purpose o preventing the increaseo endotoxin (and microbial) contamination that, subsequently,cannot be destroyed or removed.

Pyrogens can be destroyed by heating at high temperatures. A typical procedure or depyrogenation o glassware and equip-ment is maintaining a dry heat temperature o 250°C or 45min. Exposure o 650°C or 1 min or 180°C or 4 hours, like-wise, will destroy pyrogens. The usual autoclaving cycle will not

do so. Heating with strong alkali or oxidizing solutions destroypyrogens. It has been claimed that thorough washing with dtergent will render glassware pyrogen-ree, i subsequentrinsed thoroughly with pyrogen-ree water. Rubber stoppecannot withstand pyrogen-destructive temperatures, so reance must be on an eective sequence o washing, thorougrinsing with WFI, prompt sterilization, and protective storage ensure adequate pyrogen control. Similarly, plastic containeand devices must be protected rom pyrogenic contaminatioduring manuacture and storage, since known ways o destroying pyrogens aect the plastic adversely. It has been reporte

that anion-exchange resins and positively-charged membranflters remove pyrogens rom water. Also, although reverse omosis membranes will eliminate them, the most reliable metod or their elimination rom water is distillation.

A method that has been used or the removal o pyrogenrom solutions is adsorption on adsorptive agents. Howevesince the adsorption phenomenon may also cause selective rmoval o chemical substances rom the solution, this methohas limited application. Other in-process methods or thedestruction or elimination include selective extraction procdures and careul heating with dilute alkali, dilute acid, or mioxidizing agents. In each instance, the method must be studiethoroughly to be sure it will not have an adverse eect on thconstituents o the product. Although ultrafltration now makpyrogen separation on a molecular-weight basis possible an

the process o tangential ow is making large-scale processinmore practical, use o this technology is limited, except in bitechnological processing.

sOUrCes O PyrOgens

Through understanding the means by which pyrogens macontaminate parenteral products, their control becomes moachievable. Thereore, it is important to know that water probably the greatest potential source o pyrogenic contamintion, since water is essential or the growth o micro-organismand requently contaminated with gram-negative organism When micro-organisms metabolize, pyrogens will be produceThereore, raw water can be expected to be pyrogenic and onwhen it is appropriately treated to render it ree rom pyrogensuch as WFI, should it be used or compounding the product orinsing product contact suraces, such as tubing, mixing vesseland rubber closures. Even when such rinsed equipment ansupplies are let wet and improperly exposed to the environment, there is a high risk they will become pyrogenic. Althougproper distillation will provide pyrogen-ree water, storage conditions must be such that micro-organisms are not introduceand subsequent growth is prevented.

Other potential sources o contamination are containers anequipment. Pyrogenic materials adhere strongly to glass another suraces, especially rubber closures. Residues o solutionin used equipment oten become bacterial cultures, with subsquent pyrogenic contamination. Since drying does not destropyrogens, they may remain in equipment or long periods. Aequate washing reduces contamination, and subsequent dryheat treatment can render contaminated equipment suitabor use. However, all such processes must be validated to ensur

eectiveness. Aseptic processing guidelines require validatioo the depyrogenation process by demonstrating at least 3-loreduction in an applied endotoxin challenge.

Solutes may be a source o pyrogens. For example, the manacturing o bulk chemicals may involve the use o pyrogenwater or process steps, such as crystallization, precipitation, owashing. Bulk drug substances derived rom cell culture ermentation will almost certainly be heavily pyrogenic. Thereore, alots o solutes used to prepare parenteral products should btested to ensure they will not contribute unacceptable quantties o endotoxin to the fnished product. It is standard practictoday, to establish valid endotoxin limits on active pharmaceutical ingredients and most solute additives.





The manuacturing process must be carried out with greatcare and as rapidly as possible, to minimize the risk o micro-bial contamination. Preerably, no more product should be pre-pared than can be processed completely within one workingday, including sterilization.

PrODUCtiOn aCilities

The production acility and its associated equipment must bedesigned, constructed, and operated properly or the manu-acture o a sterile product to be achieved at the quality level

required or saety and eectiveness. Materials o constructionor sterile product production acilities must be ‘smooth, clean-able, and impervious to moisture and other damage’. Further,the processes used must meet cGMP standards. Since the ma- jority o SVIs are aseptically processed (fnished product notterminally sterilized), strict adherence to cGMP standards withrespect to sterility assurance (particularly, the FDA and EU aseptic processing guidance documents, which can be oundat http://www.da.gov/downloads/Drugs/GuidanceCompliance-RegulatoryInormation/ Guidances/ucm070342.pd and Eudra.ex Vol 4, Annex I. Manuacture o Sterile Medicinal Products,http://ec.europa.eu/health/fles/eudralex/vol-4/2008_11_25_gmp-an1_en.pd) is essential.

UnCtiOnal areas

To achieve the goal o a manuactured sterile product o ex-ceptionally high quality, many unctional production areas areinvolved: warehousing or procurement; compounding (ormula-tion); materials (containers, closures, equipment) preparation;fltration and sterile receiving; aseptic flling; stoppering; lyophi-lization (i warranted); and packaging, labeling, and quarantine.The extra requirements or the aseptic area are designed to pro-vide an environment where a sterile uid may be exposed to theenvironment or a brie period during subdivision rom a bulkcontainer to individual-dose containers, without becoming con-taminated. Contaminants, such as dust, lint, and other particlesand micro-organisms, are ound oating in the air, lying on coun-ters and other suraces, attached to clothing and body suraces o personnel, concentrated in the exhaled breath o personnel, anddeposited on the oor. The design and control o an aseptic area

is directed toward reducing the presence o these contaminants,so they are no longer a hazard to aseptic flling. Although the aseptic area must be adjacent to support areas,

so an efcient ow o components may be achieved, barriersmust be provided to minimize ingress o contaminants to thecritical aseptic area. Such barriers may consist o a variety o orms, including sealed walls, manual or automatic doors, air-lock pass-throughs, ports o various types, or plastic curtains.Figure 26-6 shows an example o a oor plan or a clinical sup-ply production acility (selected as an example o a small-scale,noncomplex acility) in which the two fll rooms and the stagingarea constitute the walled critical aseptic area, access to whichis only by means o pass-through airlocks. Adjacent support ar-eas (rooms) consist o glass preparation, equipment wash, cap-ping, manuacturing (compounding), and various storage areas.Figure 26-7 shows an example o a Class 100/Grade A small

scale flling room with operators properly gowned and practic-ing good aseptic techniques.

lOw Plan

In general, the components or a parenteral product ow romthe warehouse, ater release, to either the compounding area, asor ingredients o the ormula, or the materials support area, asor containers and equipment. Ater proper processing in theseareas, the components ow into the security o the aseptic areaor flling o the product in appropriate containers. From therethe product passes into the quarantine and packaging area,where it is held until all necessary tests have been perormed. I the product is to be sterilized in its fnal container, its passage

is interrupted ater leaving the aseptic area or subjection tothe sterilization process. Ater the results rom all tests areknown, the batch records have been reviewed, and the prod-uct has been ound to comply with its release specifcations, it

passes to the fnishing area or fnal release or shipment. There,sometimes, are variations rom this ow plan to meet the spe-cifc needs o an individual product or to conorm to existingacilities. Automated operations have much larger capacity andconvey the components rom one area to another with little orno handling by operators.

C roo Cfd a

Due to the extremely high standards o cleanliness and puritythat must be met by parenteral products, it has become standardpractice to prescribe specifcations or the environments (cleanrooms) in which these products are manuactured (Table 26-4). Table 26-4A compares US and European classifcations and

u 26-6. Floor plan o aseptic flling rooms and staging roomwith adjacent support areas.

u 26-7. Properly gowned and trained aseptic processing op-erators in a Class 100/Grade A Clean Room. (Courtesy o Dr. LauraThoma, The University o Tennessee College o Pharmacy.)





Table 26-4A. C roo Cfco

European United States International Society o Max No. o Particles Max No. o Particles

Grade Classifcatio Pharm. Eg. Descriptio per m 3 >/= 0.5 μm per m 3 >/= 5 μm

A 100 Critical 3,500 0

B 100 Clea 3,500 0

C 10,000 Cotrolled 350,000 2,000

D 100,000 Pharmaceutical 3,500,000 20,000

Table 26-4B. isO 14644 Cfco o Coo Pc l

ISOClassifcation Maximum Concentration Limits (Particles per Cubic Meter o Air) or Particles≥ the Sizes per Each Column

0.1 μ 0.3 μ 0.5 μ 1 μ 5 μ

1 10 - - - -

2 100 10 4 - -

3 1,000 102 35 8 -

4 10,000 1,020 352 83 -

5 100,000 10,200 3,520 832 29

6 1,000,000 102,000 35,200 8320 290

7 - - 352,000 83,200 2,930

8 - - 3,520,000 832,000 29,300

9 - - - 8,320,000 293,000

clean room designations assigned by the International Societyo Pharmaceutical Engineers. Table 26-4B provides the Inter-national Standards Organization (ISO) 14644 Classifcation o Cleanroom Particle Limits adhered to by the parenteral manu-acturing industry. Table 26-4A numbers are based on the maxi-mum allowed number o airborne particles/t3 or particles/m3 o 0.5 μm or larger size and, or Europe, 5.0 μm or larger size.The classifcations used in pharmaceutical practice normallyrange rom Class 100,000 (Grade D) or materials support areasto Class 100 (Grade A) or aseptic areas. To achieve Class 100conditions, HEPA flters are required or the incoming air, with

the euent air sweeping the downstream environment at a uni-orm velocity, 100 t/min ± 20%, along parallel lines (laminar airow). HEPA flters are defned as 99.99% or more efcient inremoving, rom the air, 0.3 μm particles generated by vaporiza-tion o the hydrocarbon Emory 3004.

Because so many parenteral products are manuactured atone site or global distribution, air quality standards in asep-tic processing areas must meet both US and European re-quirements. European standards dier rom US standards, asEuropean standards:

• use Grades A, B, C, and D classifcations, rather thanClass X (100, 1,000, etc);

• use particle and microbial limits per cubic meter, ratherthan per cubic oot;

• require particle measurements at 5 microns in addition to

0.5 microns in Grade A and B areas; and• dierentiate area cleanliness dynamically and ‘at rest.’

For the sake o convenience, the remainder o this chapteruses Class X (e.g., 100, 1,000, 10,000, 100,000) designations,although it is recognized that the use o Grades or ISO numbersare more contemporary.

Air Cleaning—Since air is one o the greatest potential sourc-es o contaminants in clean rooms, special attention must begiven to air drawn into clean rooms by the heating, ventilating,and air conditioning (HVAC) systems. This may be done by aseries o treatments that vary somewhat rom one installationto another.

In one such series, air rom the outside, frst, is passethrough a preflter, usually o glass wool, cloth, or shreddeplastic, to remove large particles. Then, it may be treated bpassage through an electrostatic precipitator. Such a unit induces an electrical charge on particles in the air and removethem by attraction to oppositely charged plates. The air thepasses through the most efcient cleaning device, a HEPA flte

For personnel comort, air conditioning and humidity control should be incorporated into the system. The latter is alsimportant or certain products, such as those that must blyophilized, and or the processing o plastic medical device

The clean, aseptic air is introduced into the Class 100 area anmaintained under positive pressure, which prevents outside arom rushing into the aseptic area through cracks, temporariopen doors, or other openings.

Laminar-Flow Enclosures—The required environmentcontrol o aseptic areas has been made possible by the use olaminar airow, originating through a HEPA flter, occupyinone entire side o the confned space. Thereore, it bathes thtotal space with very clean air, sweeping away contaminantThe orientation or the direction o airow can be horizont(Figure 26-8A) or vertical (Figure 26-8B) and may involve a limited area, such as a workbench, or an entire room. Figure 26shows a syringe-flling line in a Grade A/Class 100 area usinvertical laminar airow. The machine is placed in a convetional clean room with vertical LF provided through either thceiling or a LF hood on top o the machine. The machine guar

ing is a stainless steel rame that can hold the LF hood. Thpanes are saety glass. This could be an example o a Restricte Access Barrier System (RABS), although there are no glovinstalled, thus, requiring doors to be open to access the equiment, which is contrary to the requirements o an authentRABS. The area outside the RAB can be maintained at a slightlower level o cleanliness than that inside, perhaps Class 10,00down to Class 1,000.

Critical areas o processing, wherein the product or producontact suraces may be exposed to the environment, even orbrie period o time, must meet Class 100 clean room standard

Any contamination introduced upstream by equipment, armo the operator, or leaks in the flter will be blown downstream





In the instance o horizontal ow, this may be toward the criti-cal working site, the ace o the operator, or across the room.Should the contaminant be, or example, penicillin powder, abiohazard material, or viable micro-organisms, the danger tothe operator is apparent.

Further, great care must be exercised to prevent cross-contamination rom one operation to another, especially with

horizontal laminar air ow. For most large-scale operations,as shown in Figure 26-8B and Figure 26-9, a vertical systemis much more desirable, with the air owing through perora-tions in the countertop or through return louvers at oor level,where it can be directed or decontamination. Laminar-ow en-vironments provide well-controlled work areas, only i properprecautions are observed. Any reverse air currents or move-ments exceeding the velocity o the HEPA-fltered airow mayintroduce contamination, as may coughing, reaching, or othermanipulations o the operator. Thereore, laminar-ow work ar-eas should be protected by being located within controlled envi-ronments. Personnel should be attired or aseptic processing, assubsequently described. All movements and processes shouldbe planned careully, to avoid the introduction o contamina-tion upstream o the critical work area. Checks o the air streamshould be perormed initially and at regular intervals (usually

every six months), to be sure no leaks have developed throughor around the HEPA flters.

Clean room design, traditionally, has Class 100 rooms adja-cent to Class 100,000 rooms. Regulatory authorities have raisedgreat concerns about this signifcant change in air quality romcritical to controlled areas. It is now preerable to have an areaclassifed rom Class 1,000 to Class 10,000 in a buer area be-tween a Class 100 and Class 100,000 area.

Materials Support Area—This area is constructed to with-stand moisture, steam, and detergents and is, usually, a Class100,000 clean room. The ceiling, walls, and oor should be con-structed o impervious materials, so moisture runs o and isnot held. One o the fnishes with a vinyl or epoxy-sealing coat

A

A: Prefilter

B: Exhaust HEPA filter C: Glazed panel

D: Controlled air entry

E: Dished work-top,with peripheral slots

C

D

B

E

30%

30%

u 26-8. Horizontal and vertical laminar air ow. (Courtesy o Cosslett AG, The design o controlled environments. In: DenyerSP, Baird RM, eds. Guide to Microbiological Control in Pharmaceuticals and Medical Devices, 2nd ed. London: CRC Press, Taylor& Francis, 2007: 69–88.)

u 26-9. High speed syringe flling machine or pre-sterilized sy-ringes. (Courtesy o Robert Bosch GmbH.)





provides a continuous surace ree rom all holes or crevices. All such suraces can be washed at regular intervals to keepthem thoroughly clean. These areas should be exhausted ad-equately, so the heat and humidity are removed or the comorto personnel. Precautions must be taken to prevent the accu-mulation o dirt and the growth o micro-organisms due to thehigh humidity and heat. In this area, preparation or the fllingoperation, such as cleaning and assembling equipment, is un-dertaken. Adequate sink and counter space must be provided.This area must be cleanable, and the microbial load must bemonitored and controlled. Precautions must also be taken to

prevent deposition o particles or other contaminants on cleancontainers and equipment, until they have been properly boxedor wrapped preparatory to sterilization and depyrogenation.

Compounding Area—The ormula is compounded in thisarea. Although it is not essential that this area be aseptic, con-trol o micro-organisms and particulates should be more strin-gent than in the materials support area. For example, meansmay need provided to control dust generated rom weighing andcompounding operations. Cabinets and counters should, pre-erably, be constructed o stainless steel. They should ft snuglyto walls and other urniture, so there are no catch areas dirt canaccumulate. The ceiling, walls, and oor should be similar tothose or the materials support area.

Aseptic Area—The aseptic area requires construction ea-tures designed or maximum microbial and particulate control.

The ceiling, walls, and oor must be sealed, so they may bewashed and sanitized with a disinectant, as needed. All coun-ters should be constructed o stainless steel and hung rom thewall, so there are no legs to accumulate dirt, where they reston the oor. All light fxtures, utility service lines, and ventila-tion fxtures should be recessed in the walls or ceiling to elimi-nate ledges, joints, and other locations or the accumulation o dust and dirt. As much as possible, tanks containing the com-pounded product should remain outside the aseptic flling area,with the product ed into the area through hose lines. Propersanitization is required, i the tanks must be moved in. Largemechanical equipment located in the aseptic area should behoused as completely as possible within a stainless steel cabi-net, to seal the operating parts and their dirt-producing tenden-cies rom the aseptic environment. Further, all such equipmentparts should be located below the flling line. Mechanical parts

that will contact the parenteral product should be demount-able, so they can be cleaned and sterilized.Personnel entering the aseptic area should enter only

through an airlock. They should be attired in sterile coverallswith sterile hats, masks, goggles, oot covers, and double gloves. Movement within the room should be minimal, and in-and-outmovement rigidly restricted during a flling procedure. The re-quirements or room preparation and the personnel may be re-laxed, i the product is to be sterilized terminally in a sealedcontainer. Some are convinced, however, it is better to have onestandard procedure meeting the most rigid requirements.

Isolation (Barrier) Technology—Isolator (or barrier) tech-nology has long been used in the pharmaceutical industry andranges rom simple screens to restricted access barriers (RABS)to ull isolation systems, all designed to isolate aseptic opera-tions rom personnel and the surrounding environment. Steril-

ity tests are now almost exclusively conducted within isolators. A alse-positive sterility test is practically unheard o these days,such that, i a positive test does occur, it likely is a true contam-ination, not as a result o contamination introduced during thetest. Isolation technology in various ormats has been adaptedto automated, large-scale, aseptic flling operations.24 An exam-ple o a sterility test isolator is shown in Figure 26-10, and anexample o a flling operation within an isolator is shown in Fig-ure 26-11. The sealed enclosures are presterilized, usually withperacetic acid, hydrogen peroxide vapor, or steam. Sterile sup-plies are introduced rom sterilizable movable modules throughuniquely engineered transer ports or directly rom attachedsterilizers, including autoclaves and hot-air sterilizing tunnels.

Results have been very promising, giving expectation o signifcantly enhanced control o the aseptic processing environmen

Isolators are enclosed, usually positively pressurized uniwith high efciency particulate air (HEPA) flters, supplyinISO 5 airow in a unidirectional manner to the interior. Arecirculates by returning it to the air handlers through sealeductwork. Cleaning can be manual or automated (clean-inplace). Access to an isolator is through glove ports and steritranser systems. Isolators can be located in an ISO 8 or bettenvironment.

The operations are perormed within windowed, sealed wallwith operators working through glove ports. The sealed enclosures are presterilized, usually with peracetic acid, hydrogeperoxide vapor, or steam. Sterile supplies are introduced rom

sterilizable, movable modules, through uniquely engineeretranser ports or directly rom attached sterilizers, includinautoclaves and hot-air sterilizing tunnels.

Recent isolator development has been signifcant, and sucsystems are now better specifed than ever. In advanced aseptprocessing acilities, it has been proven that isolators can prvide zero colony orming unit (0 cu) contamination in proceoperations, whereas the background environment is only at IS8 - EC grade D level. However, cost-savings in cleanroom construction and operation may be oset by the construction anvalidation costs o the isolator system.

For existing production lines, where conversion rom conventional flling to flling within an isolator is time and co

u 26-10. Example o sterility test isolator with vapor phase hdrogen peroxide generator. (Courtesy o Baxter Healthcare Corportion.)

u 26-11. Example o a large-scale flling line within an isolato(Courtesy o Robert Bosch GmbH.)





prohibitive, modifcations o isolation systems, RABS, have beenapplied. RABS oer a combined physical (e.g., plexiglas parti-tions) and aerodynamic barrier, ideally controlled by positivepressure with clean-air fltration, providing air exchanges andparticulate clean-up or an ISO 5 critical process zone. RABScome in two types—‘passive,’ where there is no in-process opendoor access; and ‘active,’ where, under certain validated systemconfgurations and control conditions, access may be included.

Several actors have contributed to the increased importanceand utilization o barrier isolator technology:

1. The high level o concern rom manuacturers and regula-tory agencies over the level o sterility assurance inaseptic processing.

2. Continued, relatively high level o product recalls, dueto concerns—proven or suspected—over contaminationpotential.

3. The surge o potential heat-labile products rom bio-technology and the inability to terminally sterilize thesemolecules. There are needs to control the environmentnot only rom contamination, but also with respect tostability considerations—temperature, humidity, and, i necessary, anaerobics.

4. Many new drug compounds are cytotoxic or otherwisehighly potent, where saety considerations demand sepa-ration o these drugs rom human operators.

5. Because so many biopharmaceutical drugs are so expen-sive, there is a trend toward smaller batch production.Smaller batch production makes construction o largemanuacturing acilities unnecessary, yet there is still theneed to manuacture in Class 100/Grade A/ISO 5 cleanrooms. Isolators are ideal or smaller acilities, plus aremuch more economical rom the standpoint o capital,labor and maintenance, and operator (e.g., number o employees, gowning) costs.

The main eatures o barrier/isolator technology are the abil-ity to sterilize (more than sanitize) the environment to whichsterile solution is exposed during flling and stoppering and theremoval o direct human contact with the exposed sterile prod-uct. Isolators not only protect the product rom potential hu-man contamination, but also protect the human rom potential

toxic eects o direct exposure to the drug product, especiallyimportant or cytotoxic drugs.

maintenanCe O Clean rOOms

Maintaining the clean and sanitized conditions o clean rooms,particularly the aseptic areas, requires diligence and dedicationo expertly trained custodians. Assuming the design o the a-cilities is cleanable and sanitizable, a careully planned cleaningschedule should be developed, ranging rom daily to monthly,depending on the location and its relation to the most criti-cal Class 100 areas. Tools used should be non-linting, designedor clean room use, held captive to the area, and, preerably,sterilizable.

Liquid disinectants (sanitizing agents) should be selectedcareully, due to data showing their reliable activity against

inherent environmental micro-organisms. They should be rec-ognized as supplements to good housekeeping, never as substi-tutes. They should be rotated with sufcient requency to avoidthe development o resistant strains o micro-organisms. Figure26-12 eatures an example o the ‘three bucket’ system used tosanitize acilities. One bucket is to remove as much o the rem-nant o the ‘dirty’ mop or sponge, the second bucket containsa rinse solution to help clean the mop/sponge, and the thirdbucket contains the sanitizing solution. The sanitizing solutionshould be rendered sterile prior to use, although, once in use, itwill no longer be sterile.

It should be noted that ultraviolet (UV) light rays o 237.5 nmwavelength, as radiated by germicidal lamps, are an eective

surace disinectant. However, it must also be noted that theyare only eective, i they contact the target micro-organismsat a sufcient intensity or a sufcient time. The limitationso their use must be recognized, including no eect in shadow areas, reduction o intensity by the square o the distance romthe source, reduction by particulates in the ray path, and thetoxic eect on epithelium o human eyes. It is stated that anirradiation intensity o 20 μw/cm2 is required or eective anti-bacterial activity.

PersOnnel

Personnel selected to work on the preparation o a parenteralproduct must be neat, orderly, and reliable. They should be ingood health and ree rom dermatological conditions that mightincrease the microbial load. I personnel show symptoms o ahead cold, allergies, or similar illness, they should not be per-mitted in the aseptic area, until recovery is complete. However,a healthy person with the best personal hygiene will still shedlarge numbers o viable and nonviable particles rom body sur-aces.25 This natural phenomenon creates continuing problems,when personnel are present in clean rooms; eective trainingand proper gowning can reduce, but not eliminate, the problemo particle shedding rom personnel.

Aseptic-area operators should be given thorough, ormaltraining in the principles o aseptic processing and the tech-niques to be employed.26 Subsequently, the acquired knowl-edge and skills should be evaluated, to assure that training has

been eective, beore personnel are allowed to participate inthe preparation o sterile products. Retraining should be per-ormed on a regular schedule to enhance the maintenance o the required level o expertise. An eort should be made to im-bue operators with an awareness o the vital role they play indetermining the reliability and saety o the fnal product. Thisis especially true o supervisors, since they should be individu-als who not only understand the unique requirements o asepticprocedures, but are able to obtain the ull participation o otheremployees in ulflling these exacting requirements.

The uniorm worn is designed to confne the contaminantsdischarged rom the body o the operator, thereby preventingtheir entry into the production environment. For use in the

u 26-12. Three bucket sanitizing system. (Courtesy o Contec,

Inc. and Steve Fincher Photography.)





aseptic area, uniorms should be sterile. Fresh, sterile uniormsshould be used ater every break period or whenever the indi-vidual returns to the aseptic area. In some plants, this is not

required, i the product is to be sterilized in its fnal container.Uniorms, usually, consist o coveralls or both men and women,hoods to cover the hair completely, ace masks, and Dacron orplastic boots (Fig. 26-7 and Fig. 26-13). Sterile rubber or latex-ree gloves are also required or aseptic operations, precededby thorough scrubbing o the hands with a disinectant soap.Two pairs o gloves are put on, one pair at the beginning o thegowning procedure, the other pair ater all other apparel hasbeen donned. In addition, goggles are required to complete thecoverage o all skin areas.

Dacron or Tyvek uniorms are usually worn, are eective bar-riers to discharged body particles (viable and nonviable), areessentially lint-ree, and are reasonably comortable. Air show-ers are sometimes directed on personnel entering the process-ing area to blow loose lint rom the uniorms.

Gowning rooms should be designed to enhance pregowning

and gowning procedures by trained operators, so it is possibleto ensure the continued sterility o the exterior suraces o thesterile gowning components. Degowning should be perormedin a separate exit room.

envirOnmental COntrOl evalUatiOn

Manuacturers o sterile products use extensive means to con-trol the environment, so these critical injectable productscan be prepared ree rom contamination. Nevertheless, testsshould be perormed to determine the level o control actuallyachieved. Normally, the tests consist o counting viable andnon-viable particles suspended in the air or settled on suracesin the workspace. A baseline count, determined by averagingmultiple counts, when the acility is operating under controlledconditions, is used to establish the optimal test results expect-

ed. During the subsequent monitoring program, the test resultsare ollowed careully or high individual counts, a rising trend,or other abnormalities. I the results exceed selected alert or ac-tion levels, a plan o action must be put into operation to deter-mine i or what corrective and ollow-up measures are required.

The tests used measure either the particles in a volume o sampled air or the particles settling or present on suraces. Tomeasure the total particle content in an air sample, electron-ic particle counters are available, operating on the principleo the measurement o light scattered rom particles as theypass through the cell o the optical system. These instrumentsnot only count particles, but also provide a size distribution,based on the magnitude o the light scattered rom the particle.

Although a volume o air measured by an electronic particcounter will detect all particles instantly, these instrumencannot dierentiate between viable (e.g., bacterial and ungaand non-viable particles. Due to the need to control the levo micro-organisms in the environment in which sterile products are processed, it is also necessary to detect viable particleThese are usually ewer in number than non-viable particleand are only detectable as colony-orming units (CFUs) atersuitable incubation period at, or example, 30°C to 35°C or uto 48 hours. Thus, test results will not be known until 48 houater the samples are taken, unless more rapid microbial te

procedures become dependable and acceptable.Locations or sampling should be planned to reveal poten

tial contamination levels that may be critical in the control the environment. For example, the most critical process steis usually the flling o dispensing containers, a site obviousrequiring monitoring. In act, the FDA aseptic processing guidlines require air particle counts be measured during actual fing and closing operations and not more than one oot rom thactual work site.27 Other examples include the gowning roomhigh-trafc sites in and out o the flling area, the penetration conveyor lines through walls, and sites near the inlet and exo the air system.

The sample should be large enough to obtain a meaningul particle count. At sites where the count is expected to blow, the size o the sample may need increased; or exampl

in Class 100 areas, Whyte and Niven28

suggest that the sampbe at least 30 t3 and, probably, much more. Many frms employ continuous particle monitoring in Class 100 areas to studtrends and/or to identiy equipment malunction.

The slit-to-agar (STA) sampler draws, by vacuum, a mesured volume o air through an engineered slit, causing the ato impact the surace o a slowly rotating nutrient agar pla(Fig. 26-14). Micro-organisms adhere to the surace o the agand grow into visible colonies counted as CFUs, since it is nknown whether the colonies arise rom a single micro-organisor a cluster.

A widely used method or microbiological sampling consiso the exposure o nutrient agar culture plates to the settling micro-organisms rom the air. This method is very simple aninexpensive to perorm, but will detect only those organismthat have settled on the plate; thereore, it does not measur

the number o micro-organisms in a measured volume o a(a non-quantitative test). Nevertheless, i the conditions o exposure are repeated consistently, a comparison o CFUs at onsampling site, rom one time to another, can be meaningul.

Whyte and Niven suggested that settling plates should be eposed in Class 100 areas or an entire fll (up to 7 to 8 hoursrather than the more common 1 hour. However, excessive dhydration o the medium must be avoided, particularly in thpath o laminar-ow air. The European Union GMP guidelineor sterile manuacture o medicinal products suggest an expsure period o not more than our hours that has been adopteby the FDA aseptic processing guidelines

The number o micro-organisms on suraces can be detemined with nutrient agar plates having a convex surace (RodaPlates;Fig. 26-15). With these, it is possible to roll the raiseagar surace over at or irregular suraces to be tested. Organ

isms are picked up on the agar and grow during subsequenincubation. This method can also be used to assess the numbo micro-organisms present on the surace o the uniorms operators, either as an evaluation o gowning technique, immediately ater gowning, or as a measure o the accumulation micro-organisms during processing. Whenever used, care mube taken to remove any agar residue let on the surace tested

(Further discussion o proposed, viable particle test methodand the counts accepted can be ound in Section <1116> ‘Mcrobial Evaluation and Classifcation o Clean Rooms and OthControlled Environments’ in the USP.)

Results rom these tests, although not available until 2 dayater sampling, are valuable to keep cleaning, production, an

u 26-13. Fully gowned personnel in Class 100/Grade A/B Clean-rooms. (Courtesy o Baxter Healthcare Corporation.)





quality-control personnel apprised o the level o contaminationin a given area and, by comparison with baseline counts, willindicate when more-extensive cleaning and sanitizing is need-ed. The results may also serve to detect environmental controldeects, such as ailure in air-cleaning equipment or the pres-ence o personnel who may be disseminating large numbers o bacteria without apparent physical ill eects.

Issues regarding environmental monitoring remain amongthe most controversial aspects o cGMP regulatory inspectionso parenteral manuacturing and testing environments. Regula-tory trends include requiring an increase in the number and re-

quency o locations monitored in the clean room and on cleanroom personnel, enorcing numerical alert and action limits,and linking environmental monitoring data to the decision torelease or reject the batch. It has been pointed out that ullygowned personnel still release a fnite number o micro-organ-isms (typically 10 to 100 cu per hour), so it is unreasonable toimpose the requirement o zero microbial contamination limitsat any location in the clean room.29

meDia ill (PrOCess simUlatiOn testing)

FDA inspections have increasingly ocused on media fll studiesthat truly simulate the production process. The media fll orprocess simulation test involves preparation and sterilization(oten by fltration) o sterile trypticase soy broth and fllingsterile containers with this broth, under conditions simulating,

as closely as possible, those characteristics o a flling processor a product. The key is designing these studies to simulateall actors that occur during the normal production o a lot(Table 26-5).27

The media fll provides a ‘one-time’ representation o thecapabilities o an aseptic processing operation. Media flls areconducted, when a new flling line or new product container isintroduced. For initial qualifcation o a line or product, threeconsecutive, separate, and successul media fll runs must takeplace. The FDA stresses that three is a minimum number o runs. Today, the term ‘successul’ means there is no growth inany o the units flled with sterile broth. All activities and in-terventions representative o each shit on each line must besimulated during the media fll. All personnel involved in theaseptic flling o a product (i.e., operators, maintenance per-sonnel, microbiology support personnel) must participate in at

least one media fll run per year. Typically, or each flling line

u 26-14. Examples o a Slit-To-Agar (STA) Quantitative AirSampler.

u 26-15. Example o a Rodac plate. (Courtesy o Baxter Health-care Corporation.)

Table 26-5. co o Cod D o md

sud

• Duration of longest run

• Worst-case environmental conditions

• Number and type of interventions, stoppages, adjustments,

trasers

• Aseptic assembly of equipment

• Number and activities of personnel

• Number of aseptic additions

• Shift breaks, changes, multiple gownings

• Number/type of aseptic equipment disconnections andcoectios

• Aseptic samples

• Line speed/conguration

• Manual weight checks

• Operator fatigue

• Container/closure types run on the line

• Temperature/relative humidity extremes

• Conditions permitted before line clearance

• Container/closure surfaces which contact formulation during

aseptic process





and process, the flling operation is validated or the smallestand largest container size that will be used.

Ater initial qualifcation, media flls are then conducted ona periodic basis, usually twice a year on the same flling line, toensure that conditions that existed during the initial qualifca-tion have been maintained. For periodic qualifcation, only onesuccessul media fll run is required. I any media fll run ailsor signifcant changes occur with the line, acility, or personnel,then the initial qualifcation media fll (three consecutive suc-cessul runs) must be conducted. Any changes in the processmust be evaluated or its level o signifcance (change control

quality system) that would necessitate a media fll validationrun. Any media fll ailure must be thoroughly investigated andollowed by multiple repeat media fll runs. It is considered in-appropriate to ‘invalidate’ a media fll run.

The number o containers flled with media, ideally, shouldbe the same as the actual number flled, according to the batchrecord or the product being validated. O course, this is un-realistic or large batch sizes. Thereore, the number o unitsflled must be sufcient to reect the eects o all worst caseflling rates. For example, operator atigue and the maximumnumber o interventions and stoppages must be incorporatedinto the media fll protocol. When media flling frst started, theacceptable rate o positives (number o containers that showedcontamination ater incubating the culture media) was 1 outo 1000 (0.1%). Later that number became 1 out o 3000 to

account or 95% confdence o a contamination rate o 0.1%.Today, 1 positive out o 3000 is no longer acceptable. Table 26-6 presents that ISO standard used to determine the minimumnumber o containers flled with media and the acceptablenumber o positives. The most common number o containersflled with media in the industry is 4750 with three consecutiveruns o 4750 used or initial perormance qualifcation o a new product and/or flling/closing line. This same number o unitsflled—4750—is also used or the routine semi-annual requali-fcation media flls. The expected number o positive media flls(growth seen upon incubation) is zero. One or more ailureslikely means there is a signifcant breach in the aseptic manu-acturing process, and the ensuing investigation must do every-thing possible to fnd the assignable cause.

Ater flling with culture media, but prior to incubation, allunits should be inverted or swirled to enable the media to

make contact with all internal suraces o the container/closuresystem.The culture media used or each media fll exercise must

be tested to ensure it will support the growth o micro-organ-isms, i they are present. Challenge organisms used in the me-dia challenge pretesting should include those isolated rom

environmental/personnel monitoring, those isolated ropositive sterility test results and USP growth promotion microrganisms. The positive control units inoculated with approxmately 100 CFUs o these challenge organisms are incubateat temperatures and times validated to show microbial growti present. Ater the 14 day incubation period o the media fcontainers, negative control units should then be inoculatewith challenge organisms, to prove the media will still suppogrowth, i present.

Inspection o media flled units, beore and ater incubatiois conducted by individuals trained as qualifed inspectors an

certifed by the quality control unit. It is permissible that anunit, ater flling, that is ound to lack integrity be rejected robeing part o the media fll incubation, just as a product viwould be rejected i a critical deect were ound. However, i media fll unit is ound damaged ater incubation is underwait must remain incubated and counted in the data or the medfll batch. Procedures must be very clear and specifc regaring samples taken during the media fll that simulate the atual sampling process and why these units are not part o thosincubated.

Other requirements o a valid media fll experiment include

• Must have the appropriate criteria or batch yield and accountability, just like a product batch.

• Must identiy any contaminant to the species level and

perorm complete investigations o ailed media flls.• FDA advocates videotape media flls to identiy personnepractices that could negatively impact the aseptic proces

• Media fll duration, according to FDA, EU, ISO, CEN (Eu-ropean Committee o Standardization), and PIC, must besufciently long to include all required manipulations ancover the same length o time normally consumed by thecommercial process. Most media flls are a minimum o 3hours; some may be as long as 24 hours.

PrODUCtiOn PrOCeDUres

The processes required or preparing sterile products constitua series o events initiated with the procurement o approveraw materials (drugs, excipients, vehicles, etc.) and primarpackaging components (containers, closures, etc.) and endin

with the sterile product sealed in its dispensing package. Eacstep in the process must be controlled very careully, so thproduct has its required quality. To ensure the latter, each process should be validated to ensure it is accomplishing what is intended to do. For example, an autoclave sterilization process must be validated by producing data showing it eectivekills resistant orms o micro-organisms; or, a cleaning proceor rubber closures should provide evidence that it is cleaninclosures to the required level o cleanliness; or, a flling proceshould provide evidence that it repeatedly delivers the correfll volume per container. The validation o processes requireextensive and intensive eort to be successul and is an integrpart o cGMP requirements.

Cleaning COntainers anD eqUiPment

Containers and equipment coming in contact with parenterpreparations must be cleaned meticulously. It should be obvous that even new, unused containers and equipment are contaminated with such debris as dust, fbers, chemical flms, another materials arising rom such sources as the atmosphercartons, the manuacturing process, and human hands. Resdues rom previous use must be removed rom used equipmenbeore it is suitable or reuse. Equipment should be reserved eclusively or use only with parenteral preparations and, wherconditions dictate, only or one product to reduce the risk ocontamination. For many operations, particularly with biologand biotechnology products, equipment is dedicated or onone product.

Table 26-6. isO 13408-1 sdd o mu

nu o Co d md d

accp nu o Po

Number o Media FillUnits

Allowable Numbero Failed Units(95% C.L.) by ISO

Allowable Numbero Failed Units bySimple Math

3,000 1 34,750 2 4

6,300 3 6

7,760 4 7

9,160 5 9

10,520 6 10

11,850 7 11

13,150 8 13

14,440 9 13

15,710 10 15

16,970 11 17





A variety o machines are available or cleaning new contain-ers or parenteral products. These vary in complexity rom asmall, hand loaded, rotary rinsers to large, automatic washerscapable o processing several thousand containers per hour.The selection o the particular type is determined largely by thephysical type o containers, the type o contamination, and thenumber to be processed in a given period o time.

Validation o cleaning procedures or equipment is another‘hot topic,’ with respect to cGMP regulatory inspections. Inad-equate cleaning processes have been a requent citing by FDA and other regulatory inspectors, when inspecting both active

ingredient and fnal product manuacturing acilities. It is in-cumbent upon parenteral manuacturers to establish scien-tifcally justifed acceptance criteria or cleaning validation.I specifc analytical limits or target residues are arbitrarilyset, this will cause concern or quality auditors. Validation o cleaning procedures can be relatively complicated, due to is-sues with sample methods (e.g., swab, fnal rinse, and testingo subsequent batch), sample locations, sensitivity o analyti-cal methods, and calculations used to establish cleaning limits.Cleaning validation involves challenging the ‘hardest to clean’suraces with a well-defned sample, typically an active pharma-ceutical ingredient (API) or a known ‘hard to remove’ substancelike a sparingly soluble pharmaceutical or ‘sticky’ protein. Thecleaning procedure is applied, using either swab samples orrinse samples obtained rom the ‘hardest to clean’ surace loca-

tions. These samples are analyzed or residual API, using eithera specifc analytical technique, such as high perormance liquidchromatography, or non-specifc method, such as total organiccarbon. Acceptance limits must be justifed that the cleaningprocedure accomplishes repeatedly beore the cleaning methodcan be considered valid. (Additional discussion o this topicis ound in Chapter 25 – Sterilization Processes and Sterility Assurance.)

CharaCteristiCs O maChinery

Regardless o the type o cleaning machine selected, certainundamental characteristics are usually required:

1. The liquid or air treatment must be introduced in such amanner that it will strike the bottom o the inside o theinverted container, spread in all directions, and smoothly

ow down the walls and out the opening with a sweepingaction. The pressure o the jet stream should be such thatthere is minimal splashing and turbulence inside. Splash-ing may prevent cleaning all areas, and turbulence mayredeposit loosened debris. Thereore, direct introductiono the jet stream within the container with control o itsow is required.

2. The container must receive a concurrent outside rinse.3. The cycle o treatment should provide a planned se-

quence, alternating very hot and cool treatments. Thefnal treatment should be an eective rinse with WFI.

4. All metal parts coming in contact with the containers andwith the treatments should be constructed o stainlesssteel or some other non-corroding and non-contaminat-ing material.

treatment CyCle

The cycle o treatments to be employed varies with the condi-tion o the containers to be cleaned. In general, loose debriscan be removed by vigorous rinsing with water. Detergents arerarely used or new containers, due to the risk o leaving de-tergent residues. However, a thermal-shock sequence in thecycle is usually employed to aid, by expansion and contraction,loosening o debris that may be adhering to the container wall.Sometimes, only an air rinse is used or new containers, i onlyloose debris is present. In all instances, the fnal rinse, whetherair or WFI, must be ultraclean, so no particulate residues arelet by the rinsing agent.

Only new containers are used or parenterals. Improvementshave been made in maintaining their cleanliness, during ship-

ment rom the manuacturer through tight, low-shedding pack-aging, including plastic blister packs.

maChinery Or COntainers

The machinery available or cleaning containers embodies thepreviously mentioned principles, but varies in the mechanics bywhich it is accomplished. In one manual loading type, the jettubes are arranged on arms like the spokes o a wheel, whichrotate around a center post through which the treatments areintroduced. An operator places the unclean containers on the jettubes, as they pass the loading point, and removes the clean con-tainers as they complete one rotation. A continuous automatedline operation, capable o cleaning hundreds o containers perhour, is shown in Figure 26-16. The vials are ed into the rotaryrinser in the oreground, transerred automatically to the cov-ered sterilizing tunnel in the center, conveyed through the wall

in the background, and discharged into the flling clean room.

hanDling ater Cleaning

The wet, clean containers must be handled in such a way thatcontamination is not reintroduced. A wet surace will collectcontaminants much more readily than a dry surace will. Forthis reason, wet, rinsed containers must be protected (e.g.,by a laminar ow o clean air until covered, within a stainlesssteel box, or within a sterilizing tunnel). In addition, micro-organisms are more likely to grow in the presence o moisture.Thereore, wet, clean containers should be dry-heat sterilized,as soon as possible ater washing. Doubling the heating period isalso adequate to destroy pyrogens; or example, increasing thedwell time at 250° rom 1 to 2 hours, however, the actual time-temperature conditions required must be validated.

Increases in process rates have necessitated the development

o continuous, automated line processing, with a minimum o individual handling, still maintaining adequate control o thecleaning and handling o the containers.17 The clean, wet con-tainers are protected by fltered, laminar-ow air rom the rins-er, through the tunnel, and until they are delivered to the fllingline (Fig. 26-16).

ClOsUres

The rough, elastic, and convoluted surace o rubber closuresrenders them difcult to clean. In addition, any residue o lubricant rom molding or surace ‘bloom’ o inorganic con-stituents must be removed. The normal procedure calls orgentle agitation in a hot solution o a mild water sotener or

u 26-16. Loading end o large conveyer vial washer or vialsrom a rotary rinser through a sterilizing tunnel with vertical lami-nar-airow protection o clean vials. (Courtesy o Baxter HealthcareCorporation.)





detergent. The closures are removed rom the solution andrinsed several times, or continuously or a prolonged peri-od, with fltered WFI. The rinsing is done in a manner thatushes away loosened debris. The wet closures are careullyprotected rom environmental contamination, sterilized, usu-ally by steam sterilization (autoclaving), and stored in closedcontainers, until ready or use. This cleaning and sterilizingprocess must also be validated with respect to rendering theclosures ree rom pyrogens. Actually, it is the cleaning andfnal, thorough rinsing with WFI that must remove pyrogens,since autoclaving does not destroy pyrogens. I the closures

were immersed during autoclaving, the solution is drained o,beore storage, to reduce hydration o the rubber compound.I the closures must be dry or use, they may be subjectedto vacuum drying at a temperature in the vicinity o 100°C.Some reeze-dried products require extremely dry closures toavoid desorption o moisture rom the closure into the mois-ture-sensitive powder during storage. This may require dryingtimes o hours, ollowing steam sterilization.

The equipment used or washing large numbers o closures isusually an agitator or horizontal basket-type automatic wash-ing machine. Due to the risk o particulate generation rom theabrading action o these machines, some procedures simplycall or heating the closures in kettles in detergent solution, ol-lowed by prolonged ush rinsing. The fnal rinse should alwaysbe with low-particulate WFI. Figure 26-17 shows an example o

a modern closure processor that washes, siliconizes, sterilizes,and transports closures directly to the flling line.It is also possible to purchase rubber closures already cleaned

and lubricated in sterilizable bags supplied by the rubber clo-sure manuacturer.

eqUiPment

All equipment should be disassembled as much as possibleto provide access to internal structures. Suraces should bescrubbed thoroughly with a sti brush, using an eective deter-gent and paying particular attention to joints, crevices, screw threads, and other structures where debris is apt to collect. Ex-posure to a stream o clean steam aids in dislodging residuesrom the walls o stationary tanks, spigots, pipes, and similar

structures. Thorough rinsing with distilled water should ollothe cleaning steps.

Due to the inherent variation in manual cleaning, the difcuaccessibility o large stationary tanks, and the need to validathe process, computer-controlled systems, usually automateknown as clean-in-place (CIP) systems, have been developeSuch an approach involves designing the system, normally ostainless steel, with smooth, rounded internal suraces anwithout crevices. That is, or example, with welded, rathethan threaded, connections. Cleaning is accomplished with thscrubbing action o high-pressure spray balls or nozzles deli

ering hot detergent solution rom tanks captive to the systemollowed by thorough rinsing with WFI. The system is oten extended to allow sterilizing-in-place (SIP), to accomplish sanitiing or sterilizing as well.

Rubber tubing, rubber gaskets, and other rubber parts mabe washed in a manner as described or rubber closures. Thoough rinsing o tubing must be done by passing WFI through thtubing lumen. However, due to the relatively porous nature rubber compounds and the difculty in removing all traces chemicals rom previous use, it is considered by some inadviable to reuse rubber or polymeric tubing. Rubber tubing mube let wet when preparing or sterilization by autoclaving.

PrODUCt PreParatiOn

The basic principles employed in the compounding o the prouct are essentially the same as those used, historically, by phamacists. However, large-scale production requires appropriaadjustments in the processes and their control.

A master ormula should be developed and be on fle. Eacbatch ormula sheet should be prepared rom the master anconfrmed or accuracy. All measurements o quantities shoube made as accurately as possible and checked by a second quafed person. Frequently, ormula documents are generated bcomputer, and the measurements o quantities o ingredients acomputer controlled. Although most liquid preparations are dipensed by volume, they are prepared by weight, since weighincan be perormed more accurately than volume measurementand no consideration needs to be given to the temperature.

u 26-17. Examples o Rubber Stopper Preparation Systems that clean, siliconize, and depyrogenate stoppers. (Courtesy o Getinge.)





Care must be taken that equipment is not wet enough to di-lute the product signifcantly or, in the case o anhydrous prod-ucts, to cause a physical incompatibility. The order o mixingo ingredients may aect the product signifcantly, particularlythose o large volume, where attaining homogeneity requiresconsiderable mixing time. For example, the adjustment o pHby the addition o an acid, even though diluted, may cause ex-cessive local reduction in the pH o the product, so adverse e-ects are produced beore the acid can be dispersed throughoutthe entire volume o product.

Parenteral dispersions, including colloids, emulsions, and

suspensions, provide particular problems. In addition to theproblems o achieving and maintaining proper reduction in par-ticle size under aseptic conditions, the dispersion must be keptin a uniorm state o suspension throughout the preparative,transer, and subdividing operations.

Biopharmaceuticals are usually extremely sensitive to manyenvironmental and processing conditions exposed to duringproduction, such as temperature, mixing time and speed, ordero addition o ormulation components, pH adjustment and con-trol, and contact time with various suraces, such as flters andtubing. Development studies must include evaluation o manu-acturing conditions to minimize adverse eects o the processon the activity o the protein.

Among many causes or protein aggregation are proteinparticles, resulting rom heterogeneous nucleation on oreign

micro- or nanoparticles, originating rom the manuacturingprocess (i.e., mixing tanks, process tubing, flter systems, fll-ing machines30 or any other stainless steel, rubber, glass, orplastic surace31) and rom the container/closure system.30 Itis well known that silicone oil, used as a lubricant or rubberclosures, on vials, on rubber plungers, in preflled syringes,and to coat the inner surace o glass syringes and cartridgescan also induce protein aggregation.32,33 Although switchingrom silicone-coated containers to plastic containers and usingcoated rubber closures, rather than siliconized rubber closures,may minimize or eliminate the problems o protein aggregation,other challenges surace, such as unknown leachate potential,sterilization o components, vendor reliability, and cost.

The ormulation o a stable product is o paramount impor-tance. Certain aspects o this are mentioned in the discussion o components o the product. (Exhaustive coverage o the topic is

not possible within the limits o this text, but urther coverageis provided in Chapters 24 [Solutions, Emulsions, Suspensionsand Extracts] and 4 [Stability o Pharmaceutical Products]). Itshould be mentioned here, however, that the thermal steriliza-tion o parenteral products increases the possibility o chemicalreactions. Such reactions may progress to completion, duringthe period o elevated temperature in the autoclave, or be initi-ated at this time but continue during subsequent storage. Theassurance o attaining product stability requires a high order o pharmaceutical knowledge and responsibility.

iltratiOn

Ater a product has been compounded, it must be fltered, i it is a solution. The primary objective o fltration is to clariya solution. A urther step, removing particulate matter down

to 0.2 μm in size, would eliminate micro-organisms and wouldaccomplish cold sterilization. A solution with a high degree o clarity conveys the impression o high quality and purity, desir-able characteristics or a parenteral solution.

Filters are thought to unction by one or, usually, a combina-tion o: 1) sieving or screening, 2) entrapment or impaction, and3) electrostatic attraction (Fig. 26-18). When a flter retains par-ticles by sieving, they are retained on the surace o the flter.Entrapment occurs when a particle smaller than the dimensionso the passageway (pore) becomes lodged in a turn or impactedon the surace o the passageway. Electrostatic attraction causesparticles opposite in charge to that o the surace o the flter poreto be held or adsorbed to the surace. It should be noted that

increasing, prolonging, or varying the orce behind the solutionmay tend to sweep particles initially held by entrapment or elec-trostatic charge through the pores and into the fltrate.

Membrane flters are used exclusively or parenteral solu-tions, due to their particle-retention eectiveness, non-shed-ding property, non-reactivity, and disposable characteristics.However, it should be noted that non-reactivity does not applyin all cases. For example, polypeptide products may show con-siderable adsorption through some membrane flters, but those

composed o polysulone and polyvinylidine diuoride (PVDF)have been developed to be essentially non-adsorptive or theseproducts. The most common membranes are composed o Cellulose esters, Nylon, Polysulone, Polycarbonate, PVDF, orPolytetrauoroethylene (Teon).

Filters are available as at membranes or pleated into cylin-ders (Fig. 26-19) to increase surace area and, thus, ow rate.Each flter in its holder should be tested or integrity beore andater use, particularly, i it is being used to eliminate micro-organ-isms. This integrity test is perormed either as the ‘bubble-pointtest’ or as the ‘diusion or orward ow’ test. The bubble pointtest is commonly used on smaller flters. As the surace area o flters becomes large, diusion o air through the water-flledpores tends to obscure the bubble point. Thereore, the diusiontest has been developed as an integrity test or flters with largesurace areas. A ‘pressure hold test’ can also be applied to large

surace area flters. The flter manuacturer will recommend thebest integrity test or the flter system in question.

These are tests to detect the largest pore or other openingthrough the membrane. The basic test is perormed by gradu-ally raising air pressure on the upstream side o a water-wet fl-ter. The bubble point is the pressure obtained when air bubblesfrst appear downstream o the flter. The diusion or orwardow test raises pressure to some point below the known bubblepoint pressure, then diusion ow (usually in mL/min) is mea-sured. These pressures are characteristic or each pore size o aflter and are provided by the flter manuacturer. For example,a 0.2-μm cellulose ester flter will bubble at about 50 psig or adiusive ow rating o no greater than 13 mL/min at a pressureo 40 psig. I the flter is wetted with other liquids, such as aproduct, the bubble point will dier and must be determinedexperimentally. I the bubble point is lower than the rated

65–75% porous high flow

Particles retained by

Sieving

Entrapment (“Tortuous pathway”)

Adsorption (Large internal surface area)

u 26-18. Membrane flter characteristics. (Courtesy o EMD Millipore Corporation.)

u 26-19. Cartridge and disc flters. Courtesy o EMD MilliporeCorporation.





pressure, the flter is deective, probably due to a puncture ortear, and should not be used.

Although membrane flters are disposable and, thus, discard-ed ater use, the holders must be cleaned thoroughly betweenuses. Today, clean, sterile, pretested, disposable assemblies orsmall, as well as large, volumes o solutions are available com-mercially. (Other characteristics o these flters, important or aull understanding o their use, are given in Chapter 14 – Sepa-ration Methods.)

There have been some reports that that 0.2 μm flters do notremove all possible microbial contamination, necessitating the

need to use certain types o 0.1 μm membrane flters. However,most o the parenteral pharmaceutical industry continues touse 0.2 μm flters, although now employing redundant (two 0.2μm flters side-by-side) fltration systems.

illing

During the flling o containers with a product, the most stringentrequirements must be exercised to prevent contamination, par-ticularly i the product has been sterilized by fltration and willnot be sterilized in the fnal container. Under the latter condi-tions, the process is called an ‘aseptic fll’ and is validated withmedia flls. During the flling operation, the product must betranserred rom a bulk container or tank and subdivided intodose containers. This operation exposes the sterile product to

the environment, equipment, and manipulative technique o theoperators, until it can be sealed in the dose container. Thereore,this operation is carried out with a minimum exposure time,even though maximum protection is provided by flling under ablanket o HEPA-fltered laminar-ow air within the aseptic area.

Most requently, the compounded product is in the orm o a liquid. However, products are also compounded as dispersedsystems (e.g., suspensions and emulsions) and as powders. A liquid is more readily subdivided uniormly and introduced intoa container having a narrow mouth than is a solid. Mobile liq-uids are considerably easier to transer and subdivide than vis-cous, sticky liquids, which require heavy-duty machinery orrapid production flling.

Although many devices are available or flling containerswith liquids, certain characteristics are undamental to themall. A means is provided or repetitively orcing a measured

volume o the liquid through the orifce o a delivery tube in-troduced into the container. The size o the delivery tube willvary rom that o about a 20-gauge hypodermic needle to a tube1/2 in or more in diameter. The size required is determined bythe physical characteristics o the liquid, the desired deliveryspeed, and the inside diameter o the neck o the container. Thetube must enter the neck and deliver the liquid well into theneck to eliminate spillage, allowing sufcient clearance to allow air to leave the container as the liquid enters. The delivery tubeshould be as large in diameter as possible to reduce resistanceand decrease velocity o ow o the liquid. For smaller volumeso liquids, delivery usually is obtained rom the stroke o theplunger o a syringe, orcing the liquid through a two-way valve,providing or alternate flling o the syringe and delivery o mo-bile liquids. For heavy, viscous liquids, a sliding piston valve,the turn o an auger in the neck o a unnel, or the oscillation o

a rubber diaphragm may be used. Also, stainless steel syringesare required with viscous liquids, because glass syringes are notstrong enough to withstand the high pressures developed dur-ing delivery. For large volumes, the quantity delivered is mea-sured in the container by the level o fll in the container, theorce required to transer the liquid being provided by gravity, apressure pump, or a vacuum pump.

The narrow neck o an ampoule limits the clearance possiblebetween the delivery tube and the inside o the neck. Since adrop o liquid normally hangs at the tip o the delivery tube atera delivery, the neck o an ampoule will be wet as the deliverytube is withdrawn, unless the drop is retracted. Thereore, fllingmachines should have a mechanism by which this drop can be

drawn back into the lumen o the tube. Since the liquid will be intimate contact with the parts o the machine through which ows, these must be constructed o non-reactive materials, sucas borosilicate glass or stainless steel. In addition, they shou

easily be demountable or cleaning and sterilization.liqUiDs

There are three main methods or flling liquids into containers with high accuracy: volumetric flling, time/pressure dosinand net weight flling. Volumetric flling machines, employinpistons or peristaltic pumps, are most commonly used.

When high-speed flling rates are desired but accuracy anprecision must be maintained, multiple flling units are ote joined in an electronically coordinated machine (Fig. 26-20 anFig. 26-21). When the product is sensitive to metals, a peristatic-pump fller may be used, because the product comes in contact only with silicone rubber tubing. However, this sacrifceflling accuracy.

Time-pressure (or time-gravity) flling machines are gaininpopularity in flling sterile liquids. A product tank is connected

the flling system equipped with a pressure sensor. The sensor cotinuously measures pressure and transmits values to the PLC sytem controlling the ow o product rom tank to flling manioldProduct ow occurs when tubing is mechanically unpinched anstops when tubing is mechanically pinched. The main advantage time/pressure flling operations is that these flling apparatuses dnot contain mechanical moving parts in the product stream. Thproduct is driven by pressure (usually nitrogen) with no pumpinmechanism involved. Thus, especially or proteins that are quisensitive to shear orces, time/pressure flling is preerable.

Most high-speed fllers or large-volume solutions use thbottle as the measuring device, transerring the liquid either bvacuum or by positive pressure rom the bulk reservoir to thindividual unit containers. Thereore, a high accuracy o fll not achievable.

The USP requires that each container be flled with a su

fcient volume in excess o the labeled volume to ensure withdrawal o the labeled volume and provides a table o suggestefll volumes.

The flling o a small number o containers may be accomplished with a hypodermic syringe and needle, the liquid drawinto the syringe and orced through the needle into the container. An example o such a device that provides greater speeo flling is the Cornwall Pipet (Becton Dickinson). The devichas a two-way valve between the syringe and the needle and means or setting the stroke o the syringe, so the same volumis delivered each time. Clean, sterile, disposable assemblieoperating on the same principle have particular useulness ihospital pharmacy or experimental operations.

u 26-20. Syringe flling machine. (Courtesy Baxter HealthcaCorporation.)





sOliDs

Sterile solids, such as antibiotics, are more difcult to subdivideevenly into containers than are liquids. The rate o ow o solidmaterial is slow and oten irregular. Even though a containerwith a larger-diameter opening is used to acilitate flling, it isdifcult to introduce the solid particles, and the risk o spillageis ever-present. The accuracy o the quantity delivered cannot

be controlled, as well as with liquids. Due to these actors, thetolerances permitted or the content o such containers mustbe relatively large.

Some sterile solids are subdivided into containers by indi-vidual weighing. A scoop is usually provided to aid in approxi-mating the quantity required, but the quantity flled into thecontainer is fnally weighed on a balance. This is a slow process. When the solid is obtainable in a granular orm, so it will ow more reely, other methods o flling may be employed. In gen-eral, these involve the measurement and delivery o a volumeo the granular material that has been calibrated in terms o the weight desired. In the machine shown in Figure 26-22, anadjustable cavity in the rim o a wheel is flled by vacuum and

u 26-21. Vial flling machine, distant and close-up views. (Cour-tesy, Baxter Healthcare Corporation.)

Principle of operation

Powder

hopper

Doctor

blade

Vacuum

Air

pressure

Ejectedpowder

slug

Filling

wheel

Dust

collection

Purge

Top

seal

Agitator

u 26-22. Perry Accofl Sterile Powder Filling Machine. A. Prin-ciple o operation. B. Filler inside a barrier system. C. Close-up view o fller. (Courtesy o M&O Perry Industries, Inc.)

A





the contents held by vacuum, until the cavity is inverted overthe container. The solid material is then discharged into thecontainer by a pu o sterile air.

sealing

amPOUles

Filled containers should be sealed as soon as possible, to pre-vent the contents rom being contaminated by the environment. Ampoules are sealed by melting a portion o the glass neck. Two

types o seals are employed normally: tip-seals (bead-seals) orpull-seals.Tip-seals are made by melting enough glass at the tip o the neck

o an ampoule to orm a bead and close the opening. These can bemade rapidly in a high-temperature gas-oxygen ame. To producea uniorm bead, the ampoule neck must be heated evenly on allsides, such as by burners on opposite sides o stationary ampoulesor by rotating the ampoule in a single ame. Care must be takento properly adjust the ame temperature and the interval o heat-ing to completely close the opening with a bead o glass. Excessiveheating results in the expansion o the gases within the ampouleagainst the sot bead seal, which causes a bubble to orm. I thebubble bursts, the ampoule is no longer sealed; i it does not, thewall o the bubble will be thin and ragile. Insufcient heating willleave an open capillary through the center o the bead. An incom-pletely sealed ampoule is called a ‘leaker’.

Pull-seals are made by heating the neck o the ampoule below the tip, leaving enough o the tip or grasping with orceps orother mechanical devices. The ampoule is rotated in the amerom a single burner. When the glass has sotened, the tip isgrasped frmly and pulled quickly away rom the body o the am-poule, which continues to rotate. The small capillary tube, thus,ormed is twisted closed. Pull-sealing is slower, but the seals aremore secure than tip-sealing. Figure 26-23 shows a machinecombining the steps o flling and pull-sealing ampoules.

Ampoules having a wide opening must be sealed by pull-seal-ing. Fracture o the neck o ampoules during sealing may occur,i wetting o the necks occurs at the time o flling. Also, wetnecks increase the requency o bubble ormation and unsightlycarbon deposits, i the product is organic.

To prevent decomposition o a product, it is sometimes nec-essary to displace theair in the space above the product in the

ampoule with an inert gas, by introducing a stream o the gas,such as nitrogen or carbon dioxide, during or ater flling withthe product. Immediately thereater, the ampoule is sealed, be-ore the gas can diuse to the outside. This process should bevalidated to ensure adequate displacement o air by the gas ineach container.

vials anD bOttles

Glass or plastic vials and bottles are sealed by closing the opeing with a rubber closure (stopper). This must be accomplisheas rapidly as possible ater flling and with reasoned care, to prvent contamination o the contents. The large opening makethe introduction o contamination much easier than with ampoules. Thereore, during the critical exposure, the open containers should be protected rom the ingress o contaminatiopreerably with a blanket o HEPA-fltered laminar airow.

The closure must ft the mouth o the container snug

enough, so its elasticity seals rigid to slight irregularities ithe lip and neck o the container. However, it must not ft ssnugly that it is difcult to introduce into the neck o the container. Preerably, closures are inserted mechanically, using aautomated process, especially with high-speed processing. Treduce riction, so the closure may slide more easily througa chute and into the container opening, the closure suraceare halogenated or treated with silicone. When the closure positioned at the insertion site, it is pushed mechanically intthe container opening (Fig. 26-24). When small lots are encountered, manual stoppering with orceps may be used, but suchprocess poses greater risk o introducing contamination thaautomated processes. This is a good test or evaluation o opertor aseptic techniques, but not recommended or any produflling and stoppering.

Container-closure integrity testing has become a major ocu

or the industry, due to emphasis by regulatory agencies. Cotainer-closure integrity measures the ability o the seal betweethe glass or plastic container opening and the rubber closurto remain tight and ft and to resist any ingress o microbicontamination during product shel lie. Container-closure integrity test requirements are covered in USP <1207>, and thvarious test methods are described by Guazzo.34

Rubber closures are held in place by means o aluminumcaps. The caps cover the closure, crimped under the lip o thvial or bottle to hold them in place. The closure cannot be rmoved without destroying the aluminum cap; it is tamperprooThereore, an intact aluminum cap is proo that the closure hanot been removed intentionally or unintentionally. Such confmation is necessary to ensure the integrity o the contents, as tsterility and other aspects o quality.

The aluminum caps are designed so the outer layer o dou

ble-layered caps, or the center o single-layered caps, can bremoved to expose the center o the rubber closure, withoudisturbing the band that holds the closure in the containeRubber closures or use with intravenous administration seoten have a permanent hole through the closure. In such casea thin rubber disk, overlayed with a solid aluminum disk,

u 26-23. FPS2CA Automatic Monoblock Closed Ampule Fillingand Sealing Machine. (Courtesy o and with permission rom Cozzoli Machine Company.)

u 26-24. Mechanical device or inserting rubber closures in vals. (Courtesy o Baxter Healthcare Corporations.)





placed between an inner and outer aluminum cap, thereby pro-viding a seal o the hole through the closure.

Single-layered aluminum caps may be applied using a handcrimper. Double- or triple-layered caps (Fig. 26-25) requiregreater orce or crimping; thereore, heavy-duty mechanicalcrimpers (Fig. 26-26) are required.

sterilizatiOn

Whenever possible, the parenteral product should be sterilized,ater being sealed in its fnal container (terminal sterilization)and within as short a time as possible ater flling and sealingare completed. Since this usually involves a thermal process,although there is a trend in applying radiation sterilization tofnished products, due consideration must be given to the eecto the elevated temperature, upon the stability o the product. Many products, both pharmaceutical and biological, are aectedadversely by elevated temperatures required or thermal steril-ization. Heat-labile products must, thereore, be sterilized bya non-thermal method, usually by fltration through bacteria-retaining flters. Subsequently, all operations must be carriedout in an aseptic manner, so contamination is not introducedinto the fltrate. Colloids, oleaginous solutions, suspensions,and emulsions that are thermolabile may require a process inwhich each component is sterilized separately and the productis ormulated and processed under aseptic conditions.

The perormance o an aseptic process is challenging, buttechnical advances in aseptic processing, including improvedautomation, use o isolator systems, ormulations to includeantimicrobial eects, and combinations o limited sterilizationwith aseptic processing, have decreased the risk o contamina-tion. Thereore, the successes realized should encourage con-tinued eorts to improve the assurance o sterility achievablewith aseptic processing. The importance o this is that, or manydrug solutions and essentially all biopharmaceutical products,aseptic processing is the only method that can be consideredor preparing a sterile product.

Interaction among environmental conditions, the constitu-ents in the closure, and the product may result in undesirableclosure changes, such as increased brittleness or stickiness,which may cause loss o container-closure seal integrity. Thus,shel lie integrity is an important consideration in closure se-

lection and evaluation.The assessment o aseptic-processing perormance is based on

the contamination rate resulting rom periodic process simula-tions using media-flling, instead o product-flling o containers. A contamination rate no greater than 0.1% at 95% confdencehas been considered indicative o satisactory perormance in theindustry. However, with current advances in aseptic processingcapabilities, lower contamination rates may be achievable.

Radiation sterilization, as mentioned, is gaining momen-tum as an alternative terminal sterilization method. There hasbeen limited understanding o the molecular transormationsthat may occur in drug molecules and excipients under expo-sure to the high-energy gamma radiation levels o the process.However, lower energy beta particle (electron beam) radiationhas seen some success. Signifcant research must still be ac-complished, beore radiation sterilization is used as a terminal

sterilization process. The use o radiation or the sterilization o materials, such as plastic medical devices, is well established.

Dry-heat sterilization may be employed or a ew dry solidsnot aected adversely by the high temperatures and or therelatively long heating period required. This method is appliedmost eectively to the sterilization o glassware and metalware. Ater sterilization, the equipment will be sterile, dry, and, i thesterilization period is long enough, pyrogen-ree.

Saturated steam under pressure (autoclaving) is the most com-monly used and the most eective method or the sterilization o aqueous liquids or substances that can be reached or penetratedby steam. A survival probability o at least 10−6 is readily achiev-able with terminal autoclaving o a thermally stable product.

u 26-25. Examples o aluminum–plastic seals. A. Flip-O Seals: Aluminum shell with a removable plastic button in order to accessstopper surace. B. Flip-Tear Seals: Aluminum shell is completely re-moved rom container by ipping o the plastic button—allows stop-per removal. (Courtesy o West Pharmaceutical Services.) (Flip-O isa registered trademark o West Pharmaceutical Services in the UnitedStates and other jurisdictions.)

u 26-26. CM200 Continuous Motion Crimping Machine. (Cour-tesy o and with permission rom Cozzoli Machine Company.)





However, it needs noted that, or terminal sterilization, the assur-ance o sterility is based on an evaluation o the lethality o the

process (i.e., o the probable number o viable microorganismsremaining in product units). However, or aseptic processing,where the components used have been sterilized separately byvalidated processes and aseptically put together, the level o ste-rility assurance is based on an evaluation o the probable numbero product units contaminated during the process.

Figure 26-27 shows an example o a modern autoclave orsterilization. Since the temperature employed in an autoclaveis lower than that or dry-heat sterilization, equipment made o materials, such as rubber and polypropylene, may be sterilized, i the time and temperature are careully controlled. As mentionedpreviously, some injections are aected adversely by the elevatedtemperature required or autoclaving. For some products, suchas Dextrose Injection, a shortened cycle, using an autoclave de-signed to permit a rapid temperature rise and rapid cooling withwater spray or other cooling methods, makes it possible to use

this method. It is ineective in anhydrous conditions, such aswithin a sealed ampoule containing a dry solid or an anhydrousoil. Other products that will not withstand autoclaving tempera-tures may withstand marginal thermal methods, such as tyndal-lization or pasteurization (e.g., 10 to 12 hours at 60°C). Thesemethods may be rendered more eective or some injections, bythe inclusion o a bacteriostatic agent in the product.

Articles to be sterilized must be properly wrapped or placed insuitable containers to permit penetration o sterilants and pro-vide protection rom contamination ater sterilization. Sheetsor bags made o special steam-penetrating paper or polymericmaterials are available or this purpose. Further, containers orbags impervious to steam can be equipped with a microbe-ex-cluding vent flter to permit adequate steam penetration andair exit. Multiple wrapping permits sequential removal o outerlayers, as articles are transerred rom zones o lower to higher

environmental quality. The openings o equipment subjected todry-heat sterilization are oten covered with metal or glass cov-ers. Laboratories oten used silver-aluminum oil or coveringglassware used or endotoxin testing. Wrapping materials com-monly used or steam sterilization may be combustible or other-wise become degraded under dry-heat sterilization conditions.

The eectiveness o any sterilization technique must be proved(validated), beore it is employed in practice. Since the goal o ster-ilization is to kill micro-organisms, the ideal indicator to prove theeectiveness o the process is a resistant orm o an appropriatemicro-organism, normally resistant spores (a biological indicator,or BI). Thereore, during validation o a sterilization process, BIso known resistance and numbers are used in association with

physical-parameter indicators, such as recording thermocoupleOnce the lethality o the process is established in association witthe physical measurements, the physical measurements can bused or subsequent monitoring o in-use processes without thBIs. Eliminating the use o BIs in direct association with humanuse products is appropriate, due to the ever-present risk o aundetected, inadvertent contamination o a product or the envronment. The number o spores and their resistance in BIs useor validation studies must be accurately known or determine Additionally, the manner in which BIs are used in validation critical and must be controlled careully.

In addition to the data printout rom thermocouples, somtimes other physical indicators are used, such as color-changand melting indicators, to give visual indication that a packagor truckload has been subjected to a sterilization process. Sucevidence can become a part o the batch record to confrm thasterilization was accomplished.

Further details concerning methods o sterilization and theapplication can be ound in Chapter 25 (Sterilization Processand Sterility Assurance). In addition, the USP provides suggestionconcerning the sterilization o injections and related materials.

reeze-Drying (lyOPhilizatiOn)

Many parenteral drugs, particularly biopharmaceuticals, atoo unstable in solution to be available as ready-to-use liqui

dosage orms. Such drugs can still be flled as solutions, placein a chamber, where the combined eects o reezing and dryinunder low pressure will remove the solvent and residual moiture rom the solute components, resulting in a dry powder thhas sufcient long term stability. The process o reeze-dryinhas taken on greater prominence in the parenteral industrydue to the advent o recombinant DNA technology. Proteinand peptides must be reeze-dried or clinical and commerciuse. There are other technologies available to produce steridry powder drug products besides reeze-drying, such as steile crystallization or spray-drying and powder flling. Howevereeze-drying is the most common unit process or manuactuing drug products too unstable to be marketed as solutions.

The term ‘lyophilization’ describes a process to produce product that ‘loves the dry state.’ However, this term does noinclude the reezing process. Thereore, although lyophilizatio

and reeze-drying are used interchangeably, reeze-drying is more descriptive term. Equipment used to reeze-dry producare called reeze-dryers or lyophilizers.

Table 26-7 lists the advantages, eatures, and disadvantageo reeze-drying.

Freeze-drying, essentially, consists o:• Freezing stage— Freezing the product solution at a tem-

perature below its eutectic (crystalline) or glass transitiotemperature.

• Primary drying stage— Removing the solvent (ice) romthe product, by evacuating the chamber, usually below 0.1torr (100 μm Hg), and subliming the ice onto a cold,condensing surace at a temperature below that o theproduct, the condensing surace being within the chambor in a connecting chamber. During primary drying, thetemperature o the product must remain slightly below it

critical temperature, called ‘collapse temperature.’ Col-lapse temperature is best measured by visual observationusing a reeze-dry microscope that simulates the reeze-drying process. Collapse temperature is similar to theeutectic or glass transition temperature o the product.

• Secondary drying stage— Removing bound water romsolute(s) to a level that assures long term stability o theproduct. This is accomplished by introducing heat to theproduct under controlled conditions, thereby provid-ing additional energy to the product to remove adsorbedwater. The temperature or secondary drying should beas high as possible, without causing any chemical deg-radation o the active ingredient. For small molecules,

u 26-27. An example o a modern autoclave or sterilization.(Courtesy o Getinge.)





the highest secondary drying temperature used is 40°C,whereas or proteins it is no more than 30°C.

A small-scale lyophilization system and its unctional compo-nents is shown in Figure 26-28. The product may be rozen on

the shel in the chamber by circulating rerigerant (usually sili-cone) rom the compressor through pipes within the shel. A-ter reezing is complete, which may require several hours, thechamber and condenser are evacuated by the vacuum pump,the condenser surace having been chilled previously by circu-lating rerigerant rom the large compressor.

Heat then is introduced rom the shel to the product un-der graded control by electric resistance coils or by circulating

silicone or glycol. Heat transer proceeds rom the shel into theproduct vial and mass transer (ice) proceeds rom the prod-uct vial by sublimation through the chamber and onto the con-denser. The process continues, until the product is dry (usually1% or less moisture, except or some proteins that require aminimum amount o water or conormational stability), leav-ing a sponge-like matrix o the solids originally present in theproduct, the input o heat being controlled so as not to degradethe product.

For most pharmaceuticals and biologicals, the liquid prod-uct is sterilized by fltration beore being flled into the dosage

container aseptically. The containers must remain open duringthe drying process to allow water vapor to escape; thereore,they must be protected rom contamination during transerrom the flling area to the reeze-drying chamber, while in thereeze-drying chamber and at the end o the drying process un-til sealed. Automated loading and unloading o product to androm the reeze-dryer shelves is now state-o-the-art, where par-tially open vials are always under the auspices o Class 100 airand human intervention is eliminated.

Freeze-dryers are equipped with hydraulic or pneumaticinternal-stoppering devices designed to push slotted rubberclosures into the vials to be sealed while the chamber is stillevacuated, the closures having been partially inserted immedi-ately ater flling, so the slots were open to the outside. I inter-nal stoppering is not available or containers, such as ampoules,

are used, fltered dry air or nitrogen should be introduced intothe chamber at the end o the process to establish atmosphericpressure.

Table 26-8 provides some guidance on a typical ormula-tion approach and initial cycle chosen to reeze-dry a typicalproduct.

Table 26-7. ad d Dd o -

D d D Ccc o d

-Dd Do o

Advatages o Freeze-Dried Products

1. Product is stored i dry state-ew stability problems

2. Product is dried without elevated temperatures

3. Good or oxyge ad/or air-sesitive drugs

4. Rapid recostitutio time

5. Costituets o the dried material remai homogeouslydispersed

6. Product is process i the liquid orm

7. Sterility o product ca be achieved ad maitaied

Disadvatages o Freeze-Dried Products

1. Volatile compouds may be removed by high vacuum

2. Sigle most expesive uit operatio

3. Stability problems associated with idividual drugs

4. Some issues associated with sterilizatio ad sterility

assurace o the dryer chamber ad aseptic loadig o vials

ito the chamber

Desired Characteristics o Freeze-Dried Products

• Itact cake• Sufciet stregth

• Uiorm color

• Sufcietly dry

• Sufcietly porous

• Sterile

• Free o pyroges

• Free o particulates

• Chemically stable

Compressor (Back of Chamber)

Chamber and

Shelves

Sample Thief

Vacuum PumpFor Thief

Condenser Vacuum Pump

Computer ControlStation

u 26-28. Example o a laboratory reeze-dryer. (Courtesy o Baxter Healthcare Corporation.)

Table 26-8. Pcc apc o -D

• Have appropriate aalytical tools ad methods i place or

ormulatio characterizatio ad stability studies

• Deped o literature, previous experiece (i oe, use

cosultats), ad what is kow about the active igrediet,

desig ad develop iitial ormulatios ad coduct

prelimiary stability ad compatibility studies

• Iitial ormulatios should use commoly-kow excipietsused i reeze-dryig

• that produce acceptable cakes with rapid recostitutio

times

• that have kow miimal collapse temperatures

• that provide the desired fished product with respect to

ature o the fal solid (crystallie or amorphous)

• Solids cotet should be betwee 5% ad 30% with a

target o 10% to 15%

• Should have several iitial ormulatios to evaluate ad

compare. Usually kow the qualitative, but ot quatitative

compositio o additives util ater iitial comparative

stability studies have bee coducted

• Determie the maximum allowable temperature permitted

durig reezig ad primary dryig

• Kow eutectic, glass trasitio, ad/or collapse

temperatures, as appropriate

• Select the appropriate size o vial ad product fll volume

• Select the appropriate rubber closure

• Low water vapor trasmissio

• no absorptio o oil vapor

• Top desig miimizes stickig to shel durig/ater

stopperig

• Determie appropriate processig parameters

( continued )





aCtOrs aeCting the PrOCess rate

From the diagram in Figure 26-29, it can be seen that the diretion o heat and mass transer causes the top o the product tdry frst with drying proceeding downward to the bottom o thvial. Thereore, as drying proceeds, there exists a three-compnent or layer system in each vial—the upper dry product, thmiddle sublimation ront, and the lower rozen liquid produc As the dried layer increases, it becomes a greater barrier or thsource o greatest resistance to the transer o mass out o thvials. This points out the importance o vial dimensions an

volume o product per vial on the efciency o the reeze-dryinprocess. I large volumes o solution must be processed, the suace area relative to the depth may be increased, utilizing largvials or by using such devices as reezing the container in slanted position to increase the surace area.

The actual driving orce or the process is the vapor presure dierential between the vapor at the surace where dryino the product is occurring (the drying boundary) and at thsurace o the ice on the condenser. The latter is determined bthe temperature o the condenser, as modifed by the insulatineect o the accumulated ice. The ormer is determined by number o actors, including:

1. The rate o heat conduction through the container andthe rozen material, both relatively poor thermal conductors, to the drying boundary, while maintaining all o the

product below its eutectic temperature.2. The impeding eect o the increasing depth o dried,

porous product above the drying boundary.3. The temperature and heat capacity o the shel itsel.

The passageways between the product surace and the condenser surace must be wide open and direct or eective opertion. The condensing suraces in large reeze-dryers may be ithe same chamber as the product or located in a separate chamber connected by a duct to the drying chamber. Evacuation the system is necessary to reduce the impeding eect that colisions with air molecules would have on the passage o watemolecules. However, the residual pressure in the system mube greater than the vapor pressure o the ice on the condenseor the ice will be vaporized and pulled into the pump, an evendetrimental to most pumps.

The amount o solids in the product, the ice crystal size, antheir thermal conductance aect the rate o drying. The morsolids present, the more impediment will be provided to thescape o the water vapor. The degree o supercooling (i.e., homuch lower the product temperature goes below its equilibriu

• Rate o reezig

• Set poit temperatures durig all three phases

• need or aealig

• Pressure durig primary dryig

• Pressure durig secodary dryig

• Stopper seatig coditios (e.g., vacuum or gas)

• Optimize ormulatio ad process based o stability

iormatio durig ad ater reeze-dryig ad ater storage

i dry state

• Use a sample thie attachmet or laboratory dryers toremove samples durig the reeze-dry cycle i order to

measure moisture, potecy, or other parameters. Provides

iormatio or fal selectio o type ad amout o

stabilizer(s), i eeded, ad the cycle parameters ecessary

to provide a acceptable fal moisture level i product

• Typical reeze-dry ormulatio compoets

Buers: Phosphate, citrate, acetate

Stabilizers: Sucrose, trehalose, glycie

Bulkig agets: Maitol, lactose

Collapse temperature modifers: Polymers, sugars

• Typical reeze-dry cycle (without kowig where to start)

• Freezig phase

• Ater loadig, cool to 5°C• Decrease shel temperature to -40°C

• Hold or 2 hours

• Primary dryig phase

• Must kow collapse temperature(Tc)

• Set shel temperature approximately 20°C above Tc but

makig sure product temperature is 5°C below Tc

• Maitai chamber pressure at 10% to 30% o vapor

pressure o ice at the primary dryig temperature

(usually 100 to 200 micros)

• Use temperature probes, pressure rise test, or dewpoit

measuremet to determie ed o primary dryig

• Secodary dryig

• Use moderate to high vacuum (typically 100 micros)

• Adjust shel temperature to 25°C to 30°C or proteis; 35°Cto 40°C or o proteis ad hold or at least 4 hours

• Adjust shel temperature to 25°C or 5°C prior to

stopperig, eutralizig ad uloadig

Thermal Fluid Shelf

Dry Cake

Sublimation Front

Frozen Solution H e a t

T r a n s f e r

M a s s T r

a n s f e r

Condenser

Vacuum

Pump

Thermal fluid circulates within the

shelves to control temperature in

chamber

Temperature difference between chamber and

condenser and pressure differential between

solution in vials and vacuum pump drives ice out of

vial and onto the condenser

Conversion of solid

(ice) to vapor in

chamber called

sublimation

Pressure gradient between

sublimation front and chamber

P

u 26-29. Schematic o heat and mass transer in the reeze dryer.





reezing point beore ice crystals frst orm) and the rate o icecrystallization defne the reezing process and efciency o pri-mary drying. The larger the size o ice crystals ormed, usuallyas a result o slow reezing, the larger the pore sizes are whenthe ice sublimes and, consequently, the aster the rate o drying. A high degree o supercooling produces a large number o smallice crystals, a small pore size when the ice sublimes in the driedlayer, and a greater resistance to water vapor transport duringprimary drying. The poorer the thermal conducting propertieso the solids in the product, the slower the rate o heat transerthrough the rozen material to the drying boundary.

The rate o drying is slow, most oten requiring 24 hours or lon-ger or completion. The actual time required, the rate o heat input,and the product temperatures used must be determined or eachproduct and then reproduced careully with successive processes.

aCtOrs aeCting OrmUlatiOn

The active constituent o many pharmaceutical products ispresent in such a small quantity that, i reeze-dried alone, itspresence would be hard to detect visually. In act, the solidscontent o the original product, ideally, should be between 5%and 30%. Thereore, excipients are oten added to increase theamount o solids. Such excipients are called ‘bulking agents;’the most commonly used bulking agent in reeze-dried ormu-lations is mannitol. However, most reeze-dried ormulationsmust contain other excipients, due to the need to buer the

product and/or to protect the active ingredient rom the adverseeects o reezing and/or drying. Thus, buering agents, such assodium or potassium phosphate, sodium acetate, and sodiumcitrate, are commonly used in reeze-dried ormulations. Su-crose, trehalose, dextran, and amino acids, such as glycine, arecommonly used lyoprotectants.

Each o these substances contributes to the appearance char-acteristics o the plug, such as whether dull and spongy or spar-kling and crystalline, frm or riable, expanded or shrunken,and uniorm or striated. Thereore, the ormulation o a productto be reeze-dried must include consideration not only o thenature and stability characteristics required during the liquidstate, both reshly prepared and when reconstituted beore use,but also the characteristics desired in the dried plug.

mODiiCatiOns in the PrOCess anD eqUiPment

In some instances, a product may be rozen in a bulk containeror in trays, rather than in the fnal container, and then handledas a bulk solid. Such a state requires a continuation o asepticprocessing conditions as long as the product is exposed to theenvironment.

When large quantities o material are processed, it may be de-sirable to use ejection pumps in the equipment system. Thesedraw the vapor into the pump and eject it to the outside, there-by eliminating the need or a condensing surace. Such pumpsare expensive and usually practical only in large installations.

Available reeze-dryers range in size rom small laboratoryunits (Fig. 26-28), with shel surace areas o approximately 5square eet to large industrial models with shel surace areas o several hundred square eet. Their selection requires consider-ation o such actors as:

• Tray area required,• Volume o water to be removed,• How the chamber will be sterilized,• Whether internal stoppering is required,• Whether separate reezers will be used or initial reezing

and condensation o the product, and• Degree o automatic operation desired.

Other actors involved in the selection and use o equipmentare considered in the literature.35

Freeze-drying is now used or research in the preservationo human tissue and is fnding increasing application in theood industry. Most biopharmaceuticals require lyophilization

to stabilize their protein content eectively. Thereore, manynewer developments in the lyophilization process ocus on therequirements o this new class o drug products.

qUality assUranCe anD COntrOl

The importance o undertaking every possible means to en-sure the quality o the fnished product cannot be overem-phasized. Every component and step o the manuacturingprocess must be subjected to intense scrutiny to be confdentquality is attained in the fnished product. The responsibilityor achieving this quality is divided appropriately in conceptand practice into Quality Assurance (QA) and Quality Control(QC). QA relates to the studies made and the plans developedor ensuring quality o a product prospectively, with a fnalconfrmation o achievement. QC embodies the carrying outo these plans during production and includes all o the testsand evaluations perormed to ensure quality exists in a spe-cifc lot o product.

The principles or achieving quality are basically the sameor the manuacture o any pharmaceutical. These are dis-cussed in Chapter 3 (Quality Assurance and Control) Duringthe discussion o preparation o injections in this chapter,mention was made o numerous quality requirements orcomponents and manuacturing processes. Here, only selectedtests characteristically required beore a fnished parenteral

product is released are discussed briey, including sterility,pyrogen, and particulate tests.

sterility test

All lots o injectables in their fnal containers must be tested orsterility, except products that are allowed to apply parametricrelease (i.e., terminally sterilized by a well-defned, ully vali-dated sterilization process, has a sterility assurance level su-fcient to omit the sterility test or release). The USP prescribesthe requirements or this test or ofcial injections. The FDA uses these requirements as a guide or testing ofcial sterileproducts. The primary ofcial test is perormed by means o fl-tration, but direct transer is used i membrane fltration is un-suitable. To give greater assurance that viable micro-organismswill grow, i present, the USP requires that all lots o culture me-

dia be tested or their growth-promotion capabilities. However,it must be recognized that the reliability o both test methodshas the inherent limitations typical o microbial recovery tests.Thereore, it should be noted that this test is not intended asa thoroughly evaluative test or a product subjected to a ster-ilization method o unknown eectiveness. It is intended as acheck test on the probability that a previously validated steril-ization procedure has been repeated or to give assurance o itscontinued eectiveness. A discussion o sterility testing is givenin Chapter 25 (Sterilization Processes and Sterility Assurance).

In the event o a sterility-test ailure, the immediate issueconcerns whether the growth observed came rom viable mi-cro-organisms in the product (true contamination) or rom ad-ventitious contamination during the testing (a alse positive).The USP does not permit a retest, unless specifc evidence isdiscovered to suggest contamination occurred during the test.

Thereore, a thorough investigation must be launched to sup-port the justifcation or perorming the retest and assessingthe validity o the retest results relative to release o the loto product.

It should be noted that a ‘lot,’ with respect to sterility test-ing, is that group o product containers that has been subjectedto the same sterilization procedure. For containers o a prod-uct that have been sterilized by autoclaving, or example, alot would constitute those processed in a particular sterilizercycle. For an aseptic flling operation, a lot would constitute allo those product containers flled during a period in which therewas no change in the flling assembly or equipment and whichis no longer than one working day or shit.





As stated previously, isolator technology has been applied tosignifcantly reduce the incidence o alse positives in the con-ductance o the sterility test. Figure 26-10 shows an exampleo a sterility testing isolator. Validation o isolator systems orsterility testing is described in USP <1208>.

PyrOgen test

The USP evaluates the presence o pyrogens in parenteralpreparations by a qualitative ever response test in rabbits, thePyrogen Test (Section <151>), and by the Bacterial Endotox-

ins Test (Section <85>). These two USP tests are described inChapter 25 (Sterilization Processes and Sterility Assurance).Rabbits are used as test animals in Section <151>, because theyshow a physiological response to pyrogenic substances similarto that o man. Although a minimum pyrogenic dose (MPD),the amount just sufcient to cause a positive USP Pyrogen Testresponse, may produce uncertain test results, a content equalto a ew times the MPD will leave no uncertainty. Thereore,the test is valid and has continued in use, since introduced bySeibert in 1923. It should be understood that not all injectionsmay be subjected to the rabbit test, since the medicinal agentmay have a physiological eect on the test animal such that anyever response would be masked.

The Bacterial Endotoxins Test (BET) is an in vitro test basedon the ormation o a gel or the development o color in the pres-ence o bacterial endotoxins and the lysate o the amebocytes o the horseshoe crab (Limulus polyphemus). The Limulus Ame-bocyte Lysate (LAL) test, as it also is called, is a biochemical testperormed in a test tube and is simpler, more rapid, and o greatersensitivity than the rabbit test. Figure 26-30 shows an example o a positive endotoxin test result in a test tube. Although it detectsonly the endotoxic pyrogens o gram-negative bacteria, theseare the most prominent environmental microbial contaminantslikely to invade sterile products. The test has been automatedand can determine the quantitative amount o endotoxin in asample. This test has enabled endotoxin limits to be establishedon fnished products and bulk drug substances and excipients.

To provide standardization or the test, the USP has estab-lished a reerence standard endotoxin (RSE) against which lotso the lysate is standardized. Thus, the sensitivity o the lysateis given in terms o endotoxin units (EU). Most USP injections

have now been given limits in terms o EUs (e.g., BacteriostaticSodium Chloride Injection, 1.0 EU/mL), thus, indicating an in-creasing priority or the BET in testing or the presence o endo-toxin in parenteral products and in medical devices.

PartiCUlate matter evalUatiOn

Particulate matter in parenteral solutions has been recognizeas unacceptable, since the user could be expected to concludthat the presence o visible dirt would suggest that the produis o inerior quality. Today, it is recognized that the presence particles in solution, particularly i injected intravenously, cabe harmul. Although data defning the extent o risk and the eects produced are still limited, it has been shown that particlo lint, rubber, insoluble chemicals, and other oreign matt

can produce emboli in the vital organs o animals and manFurther, it has been shown that the development o inusiophlebitis may be related to the presence o particulate mattein intravenous uids.

The particle size o particular concern has not been cleardelineated, but it has been suggested that, since erythrocytehave a diameter o approximately 4.5 μm, particles o morthan 5 μm should be the basis or evaluation. This is a consideably smaller particle than can be seen with the unaided eye; aproximately 50 μm is the lower limit, unless the Tyndall eeis used, whereby particles as small as 10 μm can be seen by thlight scattered rom them.

The USP specifes that good manuacturing practice requireach fnal container o an injection be subjected individualto a visual inspection and containers in which visible particlcan be seen should be discarded. This 100% inspection o a l

o product is designed to prevent the distribution and use oparenterals that contain particulate matter. Thereore, all o thproduct units rom a production line are currently being inspected individually, by human inspectors, under a good lighbaed against reection into the eye, and against a black-anwhite background. This inspection is subject to the limitatioo the size o particles that can be seen, the variation o visuacuity rom inspector to inspector, their emotional state, eystrain, atigue, and other personal actors that will aect what seen. However, it does provide a means or eliminating the eunits that normally contain visible particles. Automated inspetion machines are increasingly being used today.

The assessment o the level o particulate matter below thvisible size o about 50 μm has become an increasingly useQC indicator o process cleanliness in the manuacture o in jections. The tests used, however, are destructive o contain

units. Thereore, they are perormed on appropriately selectesamples o products. Further, all o these methods require verstringent, ultraclean preparation techniques to ensure accurcy in the counting and sizing o particles only in the producrather than those that may have been introduced inadvertentduring the sample preparation or the testing procedure.

The USP has identifed two test methods in <788>, Particulate Matter in Injections. All LVIs or single-dose inusion anthose SVIs or which the monograph specifes a limit (primarithose commonly added to inusion solutions) are subject to thspecifed limits given inTable 26-9. The frst test used is thlight obscuration test, which uses an electronic instrument dsigned to count and measure the size o particles by means oshadow cast by the particle as it passes through a high-intensilight beam. I the injection ormulation is not a clear, colorlesolution (e.g., an emulsion) or it exceeds the limits specifed othe light obscuration test, it is to be subjected to the microscoic count test. The latter method consists o fltering a measuresample o solution through a membrane flter under ultracleaconditions and then counting the particles on the surace o thflter, using a microscope and oblique light at 100× magnifction. The time requirements or perorming the latter test arvery long. These standards are readily met in the United State

today by the manuacturers o LVIs and the specifed SVIs. Whether or not these standards are realistic, toxicological

has not been established; rather, the objective o the compendium is to establish specifcation limits that encourage thpreparation o clean parenteral solutions, particularly those tbe given intravenously.u 26-30. Example o positive (let tube) endotoxin test.





Table 26-9. su Pcu m l ic Poduc

Compendia LVI/SVI Method ≥10μm ≥25μm

USP LVI Light Blockage

Microscope

25 part/mL

12 part/mL

3 part/mL

2 part/mL

USP SVI Light Blockage

Microscope

6000 part/cotai.

3000 part/cotai.

600 part/cotai.

300 part/cotai.

EP LVI

SVI Sol

SVI Powder

light Blockage

light Blockage

light Blockage

25 part/mL

6000 part/cotai.

10000 part/cotai.

3 part/mL

600 part/cotai.

1000 part/cotai.

BP LVP Coutler Couter

Light Blockage

1000 part/mL≥2μm

500 part/mL≥2μm

100 part/mL≥5μm

80 part/mL≥5μm

JP LVP Microscope 20 part/mL 2 part/mL

It also should be realized that administration sets and thetechniques used or preparing and administering intravenousinusion uids may introduce substantial amounts o particu-late matter into an otherwise clean solution. Thereore, thepharmaceutical manuacturer, the administration set manuac-turer, the pharmacist, the nurse, and the physician must shareresponsibility or making sure the patient receives a clean in-travenous injection.

COntainer/ClOsUre integrity test Ampoules that have been sealed by usion must be subjectedto a test to determine whether or not a passageway remains tothe outside; i so, all or a part o the contents may leak to theoutside and spoil the package, or micro-organisms or other con-taminants may enter. Changes in temperature during storagecause expansion and contraction o the ampoule and contents,and will accentuate interchange, i a passageway exists, even i microscopic in size.

This test is usually perormed by producing a negative pres-sure within an incompletely sealed ampoule, while the ampoule issubmerged entirely in a deeply colored dye solution. Most oten,approximately 1% methylene blue solution is employed. Ater care-ully rinsing the dye solution rom the outside, color rom the dyewill be visible within a leaker. Leakers, o course, are discarded.

Vials and bottles are not subjected to such a leaker test, be-cause the sealing material (rubber stopper) is not rigid. There-ore, results rom such a test would be meaningless. However,assurance o container-closure sealing integrity should be anintegral part o product development, by developing specifca-tions or the ft o the closure in the neck o the container, thephysical characteristics o the closure, the need or lubricationo the closure, and the capping pressure.

saety test

The National Institutes o Health requires, o most biologicalproducts, routine saety testing in animals. Under the Keauver-Harris Amendments to the Federal Food, Drug, and Cosmetic Act, most pharmaceutical preparations are now required to betested or saety. Because it is entirely possible or a parenter-

al product to pass the routine sterility test, pyrogen test, andchemical analyses, and still cause unavorable reactions wheninjected, a saety test in animals is essential, particularly orbiological products, to provide additional assurance that theproduct does not have unexpected toxic properties.

PaCkaging anD labeling

A ull discussion o the packaging o parenteral preparations isbeyond the scope o this text. It is essential, o course, thatthe packaging provide ample protection or the product againstphysical damage rom shipping, handling, and storage, as well asprotecting light-sensitive materials rom ultraviolet radiation.

PaCkaging

The USP includes certain requirements or the packaging andstorage o injections:

1. The volume o injection in single-dose containers is de-fned as that which is specifed or parenteral administra-tion at one time and is limited to a volume o 1 L.

2. Parenterals intended or intraspinal, intracisternal, orperidural administration are packaged only in single-dose

containers.3. Unless an individual monograph specifes otherwise,no multiple-dose container shall contain a volume o injection more than sufcient to permit the withdrawaland administration o 30 mL.

4. Injections packaged or use as irrigation solutions oror hemofltration or dialysis or or parenteral nutritionare exempt rom the oregoing requirements relating topackaging. Containers or injections packaged or use ashemofltration or irrigation solutions may be designed toempty rapidly and may contain a volume in excesso 1 L.

5. Injections intended or veterinary use are exempt romthe packaging and storage requirements concerning thelimitation to single-dose containers and to volume o multiple-dose containers.

labeling

The labeling o an injection must provide the physician or otheruser with all inormation needed to ensure the sae and prop-er use o the product. Since all o this inormation cannot beplaced on the immediate container and be legible, it may beprovided on accompanying printed matter.

A restatement o the labeling defnitions and requirements o the USP or injections is as ollows:

The term ‘labeling’ designates all labels and other written,printed, or graphic matter upon an immediate container orupon, or in, any package or wrapper in which it is enclosed,with the exception o the outer shipping container. The term‘label’ designates that part o the labeling upon the immediatecontainer.

The label states the name o the preparation, the percentagecontent o drug o a liquid preparation, the amount o activeingredient o a dry preparation, the volume o liquid to be addedto prepare an injection or suspension rom a dry preparation,the route o administration, a statement o storage conditions,and an expiration date. The label must state the name o thevehicle and the proportions o each constituent, i it is a mix-ture, and the names and proportions o all substances added toincrease stability or useulness.

Also, the label must indicate the name o the manuactur-er or distributor and carry an identiying lot number. Thelot number is capable o providing access to the completemanuacturing history o the specifc package, including each





single manuacturing step. The container label is so arrangedthat a sufcient area o the container remains uncovered orits ull length or circumerence to permit inspection o thecontents.

Preparations labeled or use as dialysis, hemofltration, or ir-rigation solutions must meet the requirements or injections,other than those relating to volume, and must also bear on thelabel statements that they are not intended or intravenous injection. Injections intended or veterinary use are so labeled.

reerenCes1. Yalkowsky SH et al. Formulation-related problems associated

with intravenous drug delivery. J Pharm Sci. (1998). 87: 787–796.

2. Mottu F et al. Organic solvents or pharmaceutical parenterals

and embolic liquids: a review o toxicity data. PDA J Pharm Sci

Tech. (2000). 54: 456–469.

3. Nema S et al. Excipients and their use in injectable products. PDA J Pharm Sci Tech. (1997). 51: 166–171.

4. Powell MF et al. Compendium o excipients or parenteral or-

mulations. PDA J Parenteral Sci Tech. (1998). 52: 238–311.5. Strickley RG.Parenteral ormulations o small molecules thera-

peutics marketed in the United States, Part I. PDA J Parenteral

Sci Tech. (1999). 53: 324–349.

6. Strickley RG.Parenteral ormulations o small molecules thera-peutics marketed in the United States, Part II. PDA J Parenteral

Sci Tech. (2000). 54: 69–96.7. Strickley RG.Parenteral ormulations o small molecules thera-peutics marketed in the United States, Part III. PDA J Parenteral

Sci Tech. (2000). 54: 152–169.8. Rowe RC et al. (Ed.). Handbook o Pharmaceutical Excipients,

6th ed, Washington DC: The Pharmaceutical Press, American

Pharmaceutical Association, 2009.9. Akers MJ.Excipient-drug interactions in parenteral ormulations.

J Pharm Sci. (2002). 91: 2283–2297.10. Sutton SVW,Porter D. Development o the Antimicrobial Eec-

tiveness Test as USP Chapter <51>. PDA J Parenteral Sci Tech.

(2002). 56: 300–311.11. Carpenter JF,Crowe JH. The mechanism o cryoprotection o

proteins by solutes. Cryobiology. (1988). 25: 244–250.12. Carpenter JF et al. Rational design o stable lyophilized protein

ormulations: theory and practice. In: Carpenter JF, Manning

MC, eds. Rational Design o Stable Protein Formulations. New York: Kluwer Academic, 2002.

13. Joint Commission on Accreditation o Healthcare Organizations.The Complete Guide. Chicago: JCAHO, 1997.

14. Trissel LA. Handbook on Injectable Drugs, 16th ed. Bethesda, MD: ASHP, 2010.

15. Collentro WV. Pharmaceutical Water System Design, Opera-

tion, and Validation, Englewood, CO: Interpharm Press (now CRC Press), 1998.

16. Jiang Y et al. Tungsten-induced protein aggregation: solutionbehavior. J Pharm Sci. (2009). 98: (12) 4695–4710.

17. Iacocca RG et al. Factors aecting the chemical durability o

glass used in the pharmaceutical industry. AAPS PharmSciTech. (2010). 11: 1340–1349.

18. Hoehne M et al. Adsorption o monoclonal antibodies to glassmicroparticles. J Pharm Sci. (2011). 100: 123.

19. Walther M et al. Pharmaceutical vials with extremely highchemical inertness. PDA J Pharm Sci Tech. (2002). 56: 124–129.

20. Swit R. Glass containers or parenteral products. In: Nema S,

Ludwig JD, eds. Pharmaceutical Dosage Forms: Parenteral

Medications, 3rd ed, Vol 1.London: Inorma, 2010, 287–304.

21. Pang J et al. Recognition and identifcation o UV-absorbingleachables in EPREX pre-flled syringes: an unexpected occur-

rence at a ormulation-component interace. PDA J Pharm Sci

Technol. (2007). 61: 423–432.22. Vilivalam VD, DeGrazio FL. Plastic packaging or parenteral drug

delivery. In: Nema S, Ludwig JD, eds. Pharmaceutical Dosage

Forms: Parenteral Medications, 3rd ed, Vol 1. London: Inorma,

2010,. 305–323.

23. Das REG et al. Monocyte activation test or pro-inammatory

and pyrogenic contaminants o parenteral drugs: test design andata analysis. J Immun Methods. (2004). 288: 165–177.

24. Lysjord J (Ed.). Practical Aseptic Processing: Fill and Finish, Vols 1 and 2. Bethesda, MD: Parenteral Drug Association/Davis

Healthcare, 2009.

25. Howorth H.Movement o airow, peripheral entrainment, anddispersion o contaminants. J Parenteral Sci Tech. (1988). 42:

14–19.26. Akers MJ. Good Aseptic Practices: Education and Training o

Personnel Involved in Aseptic Processing, In: MJ Groves, Murty

R, eds. Aseptic Pharmaceutical Manuacturing II. Englewood,CO: Interpharm Press (now CRC Press), 1995: 181–221.

27. US Department o Health and Human Services (2004). Guidan

or Industry: Sterile Drug Products Produced by Aseptic Pro-

cessing— Current Good Manuacturing Practice. http://www.da.gov/downloads/Drugs/GuidanceComplianceRegulatory

Inormation/Guidances/ucm070342.pd. (accessed September 2

2011).28. Whyte W, Niven L.Airborne bacteria sampling: the eect o

dehydration and sampling time. J Parenter Sci Technol. (1986)40: 182.

29. Akers JE.Science based aseptic processing. PDA J Pharm Sci

Tech. (2002). 56: 283–290.

30. Tyagi AK et al. IgG particle ormation during flling pump

operation: a case study o heterogeneous nucleation on stainlessteel nanoparticles. J Pharm Sci. (2009). 98: (1) 94–104.

31. Sharma BImmunogencity o therapeutic proteins. Part 2. Impaco container closures. Biotechnol Adv. (2007). 25: 318–324.

32. Thirumangalathu R et al. Silicone oil- and agitation-induced

aggregation o a monoclonal antibody in aqueous solution. J Pharm Sci. (2009). 98: 3167–3181.

33. Esandiary R et al. (2010). Characterization o protein aggrega

tion and adsorption on prefllable syringe suraces. http://www

westpharma.com/na/en/support/Scientifc%20Posters/ Characterization%20o % 20Protein%20Aggreagation%20and%20

Adsorption%20on%20Prefll able%20Syringe%20Systems.pd.

(accessed August 10, 2010).34. Guazzo D. Container-closure integrity testing. In: Akers MJ ed.

Sterile Drug Products—Formulation, Packaging, Manuactur-

ing, and Quality. London: Inorma Healthcare, 2010: 455–472.

35. Nail SL et al. Fundamentals o reeze-drying. In: Nail SL, Akers

MJ, eds. Development and Manuacture o Protein Pharmaceuticals. New York: Marcel Dekker, 2002: 281–360.

36. PDA technical report no. 30: parametric release o pharmaceu-ticals terminally sterilized by moist heat. PDA J Pharm Sci Tec

1999; 53: 217–222.

bibliOgraPhy

Akers MJ. Sterile Drug Products—Formulation, Packaging, Manuaturing, and Quality. London: Inorma Healthcare, 2010.

Akers MJ et al. Parenteral Quality Control, 3rd ed. New York:Dekker, 2002. Avis KE et al. (Eds.). Pharmaceutical Dosage Forms: Parenteral Med

cations, 2nd ed, Vols 1-3. New York: Dekker, 1992–1993. Avis KE et al. (Eds.). Biotechnology: Quality Assurance and Validatio

Drug Manuacturing Technology Series, Vol 4. Boca Raton, FL: CRPress, 1998.

Barber T. Control o Particulate Matter Contamination in Healthcar Manuacturing. Englewood, CO: Interpharm Press (now CRC Press2000.

Block SS (Ed.). Disinection, Sterilization and Preservation, 4th ePhiladelphia, PA: Lea & Febiger, 1991.

Carpenter JF, Manning MC (Eds.). Rational Design o Stable Prote Formulations. New York: Kluwer Academic/Plenum, 2002.

Carleton FJ, Agalloco JP (Eds.). Validation o Aseptic Pharmaceutic Processes, 2nd ed. New York: Dekker, 1998.

Coles T. Isolation Technology: A Practical Guide. Englewood, CO: Iterpharm Press (now CRC Press), 1999.

Katdare A, Chaubal MV (Eds.). Excipient Development or Pharmacetical, Biotechnology, and Drug Delivery Systems. New York, LondoInorma Healthcare, 2006.




Kuhlman H, Coleman D. Engineering aspects o WFI systems design. In: Avis KE, ed. Sterile Pharmaceutical Products: Process Engineering Applications. Bualo Grove, IL: Interpharm Press (now CRC Press),1995: 221–268.

Jameel F, Hershenson S. Formulation and Process Development Strat- egies or Manuacturing Biopharmaceuticals. Hoboken, NJ: John Wiley and Sons, Inc., 2010.

Jennings T. Lyophilization: Introduction and Basic Principles. BocaRaton, FL: CRC Press, 1999.

Luungqvist B, Reinmuller B. Clean Room Design: Mimimizing Contam- ination Through Proper Design. Boca Raton, FL: CRC Press, 1996.

Meltzer TH. High Purity Water Preparation or the Semiconductor, Phar-

maceutical and Power Industries. Littleton, CO: Tall Oaks, 1993.

Meltzer TH, Jornitz MW (Eds.). Filtration in the Biopharmaceutical Industry. New York: Dekker, 1998.

Nail SL, Akers MJ (Eds.). Development and Manuacture o Protein Pharmaceuticals. New York: Kluwers Academic/Plenum, 2002.

Nema S, Ludwig J (Eds.). Pharmaceutical Dosage Forms: Parenteral Medications, 3rd ed, 3 vols. London: Inorma Healthcare, 2010.

Phillips GB, Miller WS (Eds.). Industrial Sterilization. Durham, NC:Duke University Press, 1973.

Swarbrick J, Boylan JC (Eds.). Encyclopedia o Pharmaceutical Tech- nology, 2nd ed. New York: Dekker, 2002.

Turco S, King RE. Sterile Dosage Forms, 3rd ed. Philadelphia, PA: Lea& Febiger, 1987.

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Parenteral Preparations