Filter Validation Training-By PALL

Validation Services Seminar

Morven McAlister & Vanessa

Merefield

SLS Life Sciences TrainingMay 12, 2006

© Pall Corporation 2006

Presentation Outline

� Overview of validation tests

� Parametric Approach

� Selection of worst case test

parameters

� Product bracketing

� Additional Validation tests

� Trends / Issues


Pall Validation Sites

Validation Laboratory


Validation Definition

FDA Guideline on General Principles of Process Validation, 1987

“…establishing documented evidence which provides a high degree of

assurance that a specific process will consistently produce a product

meeting its predetermined specifications and quality attributes.”


““ Filtration is a common method of sterilizing Filtration is a common method of sterilizing

drug product solutions.drug product solutions.””FDA Guidance for Industry Sterile Drug Products Produced by Aseptic Processing

– Current Good Manufacturing Practice (2004)

Chapter IX – Validation of Aseptic Processing and Sterilization

““ For sterile products, the validation of For sterile products, the validation of

sterilisingsterilising processes should be of the same processes should be of the same

standard as for products standard as for products authorisedauthorised for for

marketingmarketing””European Guide to Good Manufacturing Practices (1998)

Annex 13 - Manufacture of investigational medicinal products

Need for Validation (1)


… may not often have resourcesand expertisewhich creates bottlenecks in

pipeline for R&D products

… may not often have resourcesand expertisewhich creates bottlenecks in

pipeline for R&D products

… have to optimize our

processes due to cost pressure

and competition in generic market

… have to optimize our

processes due to cost pressure

and competition in generic market


… regulations are changing which result in more

intensive validationand increased

clinical research

… regulations are changing which result in more

intensive validationand increased

clinical research


Global Consequences

� Growth through mergers and consolidation: Can larger companies react swiftly enoughto changes?

� Higher complexity and costs of clinical trials: Delay in bringing new compounds to market

“…“…in the last four years (2000in the last four years (2000--2003) the US FDA on 2003) the US FDA on average has approved average has approved 2222 new molecular entities (NME) new molecular entities (NME)

per year compared to an average annual approval rate of per year compared to an average annual approval rate of 3939 NMEsNMEs in the four prior yearsin the four prior years””

Leslie Platt, Ernst & Young


�“It is particularly critical to validate the

efficacy of the (sterilizing) filtration process.

�“…ensure that worst-case formulation and

processing parameters are adequately

studied, evaluated and documented.”

�“This data should be available during current

drug pre-approval inspections and for already

marketed products produced by sterile

filtration.”

FDA Human Drug CGMP Notes (1995)



� Bacterial Viability

� Establishes bactericidal properties

� Determines suitable flush protocols

� Bacterial Retention

� Confirms sterilizing capability of process membrane under worst case conditions

� Compatibility

� Confirms maintenance of filter integrity after exposure to worst case fluid and process

Filter Validation Testing - Overview


Filter Validation Testing - Overview

� Extractables

� Provides quantitative and qualitative analyses of filter extractables in model solvent

� Product-specific integrity test values (ITV)

� Establishes filter integrity test values for process filtration assembly wet with process fluid

� Adsorption Testing

� Determines extent of adsorption of product components following filtration of product


Product Information Sheet (PINS) / Process and Product Questionnaire

(PPQ)


PINS / PPQ

� Overview of customer’s fluid & process parameters

� Used to establish fluid / process-specific test

protocols representing worst case test conditions

� All information needed to complete full validation

package

� Requires exact concentration (%) of each component and carrier solvent in fluid

� Used in determining model solvent for extractables test

� Allows determination of potential testing issues, e.g.

– Bactericidal properties, Compatibility issues


Execution of Validation Package (US)

Reports reviewed and issued to customer

Customer completes Product Information Sheet

Customer contacts Pall project managers directly with any questions

Testing commences at Pall

Customer sends following items to Pall:

-Signed/approved protocols-Sample product / MSDS / PO

Pall project manager write reports

Pall writes protocols and sends to customer for approval

6-8 weeks


Product Grouping / Selection of Worst Case Conditions


FDA Guideline on Sterile Drug Products Produced by Aseptic Processing, 1987

Selection of Worst-Case Conditions for Validation Testing

“A set of conditions encompassing upper and lower processing limits and circumstances, including those within standard operating

procedures, which pose the greatest chance of process or product failure when compared to

ideal conditions”

“Filter validation should be conducted using the worst-case conditions, such as maximum filter

use time and pressure”FDA Guidance for Industry - Sterile Drug Products Produced by Aseptic

Processing – Current Good Manufacturing Practice, 2004


Parametric Validation - Aim

� Determine any effect of the fluid on the filter and on B. diminuta or suspect bioburdenisolate

� Bacterial viability and retention testing

� Compatibility testing

� Determine any effect of the filter on the product formulation

� Extractables testing

� Adsorption testing


� Product attributes

� Process parameters

� Scientific rationale

� Worst-case conditions

� Use of actual products wherever

possible

Parametric Validation - Strategy


Selection of Worst Case Conditions for Validation Testing – Product Grouping

� As per 1987 Aseptic Processing Guideline, product “families” can be grouped� “Worst case” models must be justified by scientific

rationale

� Typically, highest concentration of active under highest operating parameters (maximum process flow rate, differential pressure, temperature) represents “worst-case” model



� Considerations for product grouping

� Product components

� Test fluid should represent maximum no. components present, including active

� Concentrations of components

� Highest concentration of components typically tested

� Consider active and other constituents



� Ionic Strength � Affects surface charge of membrane and test

organism and potential adsorptive interactions

� Osmolarity � High osmolarity may cause shrinking of

microorganisms

� pH� Affects surface charge of membrane and test

organism and potential adsorptive interactions

� Affects viability of test organism

� Test extremes of pH



� Viscosity� High viscosity fluids usually require higher pressure

and/or elevated temperature processing � Typically also longer filtration duration

� Surface Tension (incl. surfactants)� Presence of surfactants (> 0.5%) can reduce

adsorptive capture

� Nutrients� Low nutrient (oligotrophic) environments may reduce

bacterial cell size / change cell surface characteristics

� Temperature� Extremes of temperature range typically tested


Bracketing of Products

Process Parameter

Active

concentration

Volume Time Flow rate Pressure Temperature

0.25 mg/mL 50 L 45 mins 1.11 L/min 0.8 bar 20ºC




10mg/mL 200 L 90 mins 2.22 L/min 0.7 bar 20ºC

20mg/mL 100 L 60 mins 1.67 L/min 1.2 bar 20ºC


Grouping of Products

Parameter

Product pH Surface

Tension

Viscosity Osmolarity Ionic

Strength

A 5.83 73.4 1.2 277 0.153

B 6.63 72.4 1.3 233 0.164

C 5.13 71.14 8.4 150 0.083

D 6.47 71.9 1.2 249 0.171

E 5.51 72.6 8.9 138 0.080

F 5.94 71.7 9.6 281 0.177


Bacterial Viability / Flush Testing (1)

� Test bacteria (~106 CFU/mL) inoculated into customer fluid and control fluid (steriledeionized (DI) water)

� Bacterial concentration monitored in fluid and control over process time

� Fluid & process established as bactericidal, moderately bactericidal or non-bactericidal


Test Methodology


Selection of Worst Case Conditions for Bacterial Viability Testing

� Actual product used� Viability determined over total contact time of

product with filter

� Maximum process temperature (≤≤≤≤ 37oC)

� If process temperature >37oC, approach for moderately bactericidal products may be required� Recirculate product at process temperature for

maximum contact time, followed by bacterial challenge in product at ≤≤≤≤ 37oC


Definition of Bactericidal

� Non-bactericidal� A decline in viability of less than one log (<90%)

in product over the process time

� Bactericidal� A decline in viability of greater than 1 log (>90%)

within 60 minutes of exposure in product

� Moderately Bactericidal� A decline in viability of less than 1 log over 60 minutes,

in conjunction with a decline in viability of 1 log or more over the process time

� May allow for an in-product challenge after productrecirculation



� Residual Effects (bactericidal fluid only)

� Removal of bactericidal fluid from test filter

� Fluid passed through test filter then rinsed with flush fluid (typically DI water)

� Additional volume of DI water passed through test filter disc, collected and inoculated with low concentration of test organism

� No. bacteria recovered from fluid must be within 30% of bacterial count recovered from control



� Recovery Flush (non-bactericidal fluids only)

� Removal of test fluid from recovery (“analysis”)

filters

� Test fluid or control inoculated with a low concentration of test bacteria

� Vacuum filtered through recovery filter and flush scheme (typically DI water) applied

� No. bacteria recovered from test fluid must be

within 30% of bacterial count recovered from control


Options for Bacterial Retention Test

Fluid Type

Challenge performed

by inoculating bacteria in fluid

directly (seeded challenge)

Fluidrecirculated

for process time followed by flush

and challenge usingsurrogate solution

inoculated with test bacteria

Fluidrecirculatedfor process

time followed by challenge using fluid

inoculated with test bacteria

Non-Bactericidal ModeratelyBactericidal

Bactericidal


Microbial Challenge –Bactericidal Fluids

“In such cases, the fluid should simulate the product as closely as practical in terms of

viscosity and other physical characteristics that are not antagonistic towards the

microbial challenge”



Challenge Fluid Selection for Bactericidal Products

� Product (short term) with flush

� Modified product (no preservative)

� Modified product (reduced or no active)

� Placebo (where appropriate)

� Surrogate fluid (e.g. saline lactose broth)

� Similar chemical properties


“The (challenge) microorganisms should be small enough to both challenge the filter's nominal porosity and simulate the smallest microorganism that may

occur in production.”


Microbial Challenge

“The microorganism Brevundimonas diminuta (ATCC 19146) when properly grown, harvested and used, is a

common challenge microorganism for 0.2 µm rated filters because of its small size (0.3 µm mean diameter)”

FDA Guidance for Industry - Sterile Drug Products Produced by Aseptic Processing – Current Good Manufacturing Practice, 2004


Section ViewChallenged with 5 x 108

B. diminuta cells per cm2

Osumi et al., PDA J. Pharma. Sci. & Technol., v. 50: pp. 30-34, (1996)

20 µm

SEM of 0.2 µm Membrane *

Typical membrane thickness ~160 µm

* Pall Ultipor® Nylon 6,6 NR Grade


Criteria for Bacterial Retention Testing of Sterilizing Grade Filters

� Brevundimonas diminuta (ATCC 19146) or other

“worst-case” bioburden isolate

� Controlled culture conditions (ASTM F838-05)

� Minimal size (B. diminuta 0.3 x 0.8 µm)

� Monodispersed

� Demonstrate penetration of 0.45 µm rated

control filter

� Simulate “worst-case" process conditions

� Total challenge ≥≥≥≥ 1 x 107 CFU/cm2

� Analyze total effluent for sterility

(Ref: ASTM-F838, PDA TR26)


� Operating parameters � Flow rate

� Differential pressure

� Filter throughput per cm2

� Total challenge duration

� Temperature

� No. batches processed per

filter assembly

� Filter sterilization conditions

Typically, maximum

values for each test parameter

Selection of Worst Case Conditions for Bacterial Challenge Testing (1)



� Flow rate and pressure are interdependent

� Validate highest flow and highest pressure to meet or exceed both process parameters

� Hydraulic shock – pulsing can be used

� B.diminuta inoculated into product wherever possible


Test Filter

� Same membrane family and pore size rating

� 47-mm membrane discs typically used from standard production

� Minimum production physical QC test limit

� “Low KL” discs

� Pall QBP (quantitative bubble point)



� Challenge method dependent on fluid properties

� Bactericidal vs. Non-Bactericidal

� Bacterial retention is confirmed if no penetration of test membrane filter occurs under test

conditions that mimic the full-scale process conditions

Bacterial Challenge


Bacterial Challenge (Non-Bactericidal Fluid)

Recirculation with Seeded Challenge Solution


Product Recirculation (Bactericidal Fluid)


Bacterial Challenge (Bactericidal Fluid)

Seeded Challenge Solution


� To quantify the amount of components adsorbed from the product onto the filter after passing through test filters

� Enables calculation of volume of product which should be flushed through process filter to ensure saturation of the filter

� Pall collects filtrates and customer performs analysis

Adsorption Testing


Adsorption TestingPeristaltic pump

Filtrate sample collection vialsProduct

Reservoir

Test filter disc in

housing

Tubing


Selection of Worst Case Conditions for Adsorption Testing

� Maximum temperature

� Maximum flow rate

� Small batch size

�Maximum filter throughput

�Maximum contact time


Compatibility Testing

� Demonstrates compatibility of specific filter with customer process fluid

� Filter exposed to process fluid for specified period under pre-determined conditions

� Compatibility determined by performing integrity tests on filter pre- and post-fluid exposure and visual examination of filter


Selection of Worst Case Conditions for Compatibility Testing

� Testing uses actual customer fluid

� Filters sterilized under maximum conditions (time/temperature) prior to product exposure

� Testing conducted at maximum process temperature

� Exposure time must be equal to process time minimally


� Potential sources:

� Hardware, support layers, membranes,

wetting agents, casting additives, etc.

Extractables Testing

OligomerAdditives

Polymer

Surface

PolymerChain

Solvent

SURFACE INTERFACE




Extractables Assessment

Filter reciprocated in extracting solvent

Solvent transferred to Rotary Evaporator

Pre-weighed Crucible


Extractables Assessment

NonNon--Volatile Residue Volatile Residue (NVR)(NVR)

Quantity

Fourier Transform InfraFourier Transform Infra--red red Spectroscopy (FTIR)Spectroscopy (FTIR)

Identity



� Qualitative and quantitative analyses of extractables from process filter

� Non-volatile residue (NVR)

� UV-Vis, FTIR

� Model solvent used based on process fluid characteristics

� Test conditions reflect process temperature and time


Advantages of NVR/IR Model System

� Wide range of models available

� NVR detects all nonvolatile material

� Flexible, widely applicable IR characterization; good for unknown identification/investigation

� Self-Validating; negative and positive controls minimize “method validation blues”


Additional Analytical Methods

� UV-Visible spectroscopy for transparent solvents

� TOC for aqueous solutions

� GC-MS for volatiles/semi-volatiles

� LC or LC/MS for nonvolatiles or heat-sensitive compounds

� ICP/MS (Inductively Coupled Plasma/Mass Spectrometry) analysis for metallic extractables, if necessary.


Selection of Worst Case Conditions for Extractables Testing (1)

� Model Solvent Approach

� Determines contribution of filter components to fluid

effluent

� Customer fluid - type and concentration of

components

� Increase solubility & concentration of low MW

weight substances in fluid due to chemical attack?

� Typically, components <10% volume do not exert

significant solubility/compatibility effects

� Fluid pH considered independently

(Ref: Weissman)


Selection of Worst Case Conditions for Extractables Testing (2)

� Process Parameters

� Temperature

� Testing conducted at temperature equal to or greater than process temperature

� Filter duration (total contact time)

� Minimum of two extraction cycles (24 hours per cycle)

� No. extractions completed is equal to or greater than total contact time of filter with product


Product-wet Integrity Test Values

Test Filter

Gauge

Pressure

RegulatorBubbles

Gas Source

Air, N2

� Bubble Point

� Forward Flow

� Pressure Hold

All three test are based on the same physics, the flow of gas through a liquid-wetted membrane under applied pressure


� Determine test parameters appropriate for establishing integrity of a filter when wet with customer fluid

� Values determined for filter wet with customer fluid and correlated to reference fluid-wet value

� Reference fluid-wet values correlated to bacterial retention (published in Filter Validation Guide).

Product-wet Integrity Test Values


Test Gas Pressure

Atmospheric pressure

Liquid-wetted Membrane

Membrane Filter Integrity Testing

� Membrane filter wetted with water or product

� Pressurized with air or N2 at validated pressure

� Flow of air through wetted membrane measured

Low diffusive gas flow through small wetted pores (integral membrane)

High convective gas flow through large pores, e.g. defective membrane areas


10

2 3 4Pressure (bar)

Flow (ml/min)

20

1

15

5

25

• • • • • • •••••

“Bubble Point”

Transition Region

Multi-point Forward Flow Curve


Diffusive flow

Transition from diffusive flow to open pore flow

Pressure

Gas Flow

Pressure

(Q/P)

Bulk gas flow through open pores

KL

KL Value Determination

KL is the pressure at which the two dotted lines cross


1

1 2 3

Pressure

Flow

2

Diffusive Flow Spectrum

KL(W)

Water wetProduct wet

KL(P)


Product Wetted Integrity Pressure

P (mbar)

Water KL Curve

KL in water

Product KL Curve

x

KL in product

FF test pressure in waterx

Calculated Test Pressure

Gas Flow

Pressure

(Q/P)

Determination of test pressure


Selection of Worst Case Conditions for Product-Wet Integrity Testing

� Product � Surface Tension

� If surface active agents present in product, surface-tension derived test pressure used

� Viscosity

� Viscous products may require extended

equilibration or test dwell times

� Process Parameters� Temperature


40 50 60Pressure (psi)

Flow (ml/min)250

Effect of Area on “Bubble Point”

200

100

150

50

0

High area cartridge Low area disc

Cartridge “bubble points” are typically lower than disc “bubble points” using the same membrane

“BP”“BP”


Critical Testing Parameters

ITV

Adsorption

Compatibility

Extractables

Bacterial Challenge

Viability

Ste

riliza

tion

C

on

ditio

ns

Te

mp

∆∆ ∆∆P

Flo

w R

ate

Tim

e

Filte

r T

hro

ug

hp

ut

Su

rfac

e

Te

ns

ion

Os

mo

larity

Vis

co

sity

Ion

ic

Stre

ng

th

pH

Co

mp

os

ition

Test Type

Considered for “worst-case”

Evaluated for information only


Additional Validation Testing


Kleenpak Connectors

Soiling Test

� Ability of KPC to produce sterile connection after intentional contamination with bacterial spores

� Male & female connector soiled with Geobacillus

stearothermophilus

� Challenge level > 105 CFU per device


Kleenpak Connectors

� Extractables Testing

� Model Solvent Approach

� Compatibility

� Tensile Strength


Disposable Systems

Tubing, bags etc

� Extractables

� FTIR, GCMS, UV

� Bioburden

� 14 day incubation period

� 2 growth media

� Endotoxin

� If product shelf-life study, qualification of assay with product required

� Sensitivity 0.005 EU/mL


Pallchek

� Extensive validation required

� Protocols currently under developments

� Various test fluids (water, buffers, media etc)

� Various ATCC bacterial strains

� Potential for product-specific validation as part of Validation services


Preparation for an audit


Preparation for an Audit (1)

� SLS Labs are not working to GMP

� Audit Hosts� QA & SLS Lab and project managers present

� SLS procedures must be available and show documented evidence that they are followed

� Training Records� Must be updated with current SOP revisions

� Evidence of competency


Validation Services – Goals / Issues


Trends in Validation Services (US)

� Increase in projects from biotechnology

companies and universities

� Increase in generic drugs

� Increase in projects from S.America

� Increase in extractables projects for pre-filters

� Decrease in project turnaround times


Trends in Validation Services -EU

� Customers requesting PWIT testing performed in triplicate

�Contract manufacturers requesting product groupings

�10-15% increase in filter validations / year

� More interaction with filter manufacturer and customer

�Increased interest in extractables


Goals - Validation Services

PINS/PPQ

� Incomplete PIN sheets frequently submitted

� Customers often lack understanding of process

� PM calls / visits customer to obtain full details

� Illegible handwriting on PIN/PPQ

� Currently PM calls for clarification

� “Typeable” PINS now complete

� PINS/PPQ to be submitted via Pall web site� Target Date – August 2006


� During customer routine QC Product Analysis unidentified peaks reported

� Traced to Pall filter cartridges

� 3 recent occurrences

� FDA/PDA recommend all extractables are identified

�More detailed analysis required

�GCMS installed in PW on May 02, 2006

�IQ/OQ currently being performed by manufacturer

�Training scheduled immediately after IQ/OQ

�Estimated target date for use in customer work – mid June 2006

�Global team needs formed to prioritize testing needs




Globalization

� Need to standardize test SOPs based on best practise globally

� Ensure data interpretation same globally

� Review validation testing prices globally

� Ability to easily communicate with global team

� Shared resources (e.g. extractables reports)

� Validation Team Room

� Shared global objectives

� V.Merefield (Europe), M.McAlister (W.Hemisphere), H. Nomura (Asia)

� First meeting held Jan 2006. Each group working on action items


�Customers requesting data to support pre-filters

(API)

�Compatibility & Extractables Data

�SLS UK and US have performed extractables

studies for a range of pre-filters & solvents

�How do we confirm compatibility?

Shared Issues - Validation Services


Test Discs

�Urgent considerations:

�Global sourcing of 47-mm discs

�Low spec media – both layers?

�Certification of 47-mm discs

� Considered a priority by global validation team

� SOP written by Chris Lewis….under review

�List of manufacturing sources for discs underway

Shared Issues - Validation Services


Additional Questions?


1. Bowman, F., M.P. Calhoun and M. White, “Microbiological methods for quality control of

membrane filters”, J. Pharm. Sci., v. 55; p. 818 (1967)

2. Pall, D.B., “Quality Control of Absolute Bacteria Removal Filters,” Bull. Parenteral Drug Assoc., 29, 392-204 (1975).

3. Howard, G. and R. Duberstein. “A case of penetration of 0.2 µm rated membrane filters by

bacteria.” Journal of the Parenteral Drug Association., v. 34; p. 95 (1980)

4. HIMA (now AdvaMed), “Microbiological Evaluation of Filters for Sterilizing Liquids,” draft

doc. No.3 Vol. 4, April, 1982 (obsolete)

5. ASTM, “Standard Test Method for Determining Bacterial Retention of Membrane Filters

Utilized for Liquid Filtration,” Standard No. F838-83 (1983, No. F838-05, rev. 2005)

6. FDA Guideline on Sterile Drug Products Produced by Aseptic Processing, 1987

7. FDA CDER Perspective on Isolator Technology, ISPE Barrier Technology Conference,

Dec. 1995

8. FDA Guidance for Industry for the Submission Documentation for Sterilization Process

Validation in Applications for Human and Veterinary Drug Products, 1994

9. FDA Human Drug CGMP Notes, Dec. 1995

10. PDA Technical Report No. 26, “Sterilizing Filtration of Liquids,” PDA J. Pharmaceutical Science and Technology, 52 (3) Supplement, 1-31, 1998

Reference Documents (1)


11. FDA Guidance for Industry - Sterile Drug Products Produced by Aseptic Processing –

current Good Manufacturing Practice, 2004

12. Weitzmann, C. The use of model solvents for evaluating extractables from filters used to process pharmaceutical products, Pharmaceutical Technology, 21 (#4), 72-99 (1997)

13. Pall Corp., “Determination of product wet integrity test values for Pall filter cartridge,” Publ. No. USTR 1471(1)

14. Sundaram, S. et al., Considerations in Using "Bubble Point" Type Tests as Filter Integrity Tests, Part I: Effect of Test Methodology on Filter Cartridge “Bubble Point” Measurements and Implications for the Use of “Bubble Point” Type Tests as Correlated Tests, Pharmaceutical Technology, Sept., 2000

15. Sundaram, S. et al., “Considerations in Using "Bubble Point" Type Tests as Filter Integrity Tests, Part II: Effect of Filter Area on “Bubble Point” Measurements and Implications for the Use of “Bubble Point” Type Tests as Correlated Tests,” Pharmaceutical Technology, Oct., 2000

16. Pall Corp., “Validation Guide for Pall 0.2 micron Ultipor N66 and N66 Posidyne Membrane Cartridges,” (1980)

17. USP General Information Chapter <1227>, Validation of Microbial Recovery from Pharmacopeial Articles, USP 27, USPC, Inc., Rockville, MD, 2004, p. 2625

18. Osumi, M., N. Yamada and M. Toya, “Bacterial retention mechanisms of membrane filters,”

PDA Journal of Pharmaceutical Science and Technology, v. 50; pp. 30-34, (1996)

Reference Documents (2)

Thank you for your attention!