Liquid forms

Department of Pharmacology & Toxicology Medical Faculty, Medical University – Sofia Dr. Rumen Nikolov, PhD

Liquid dosage forms

Liquid dosage forms are prepared: (1) by dissolving the active drugsubstance(s) in an aqueous or nonaqueous (e.g. alcohol, ether, glycerin) solvent, (2) by suspensing the drug in appropriate medium, or (3) by incorporating the drug substance into an oil or water phases.

Liquid dosage forms can be administered:• Topically - lotions or suspension applied to the skin, eye drops, nasal drops, ear drops• Orally (p.o.) - oral suspension and solution• Parenterally - subcutaneous injection (s.c.), intramuscular injection (i.m.) and intravenous administration (i.v.)

Solution (solutio)•Solutions are prepared bydissolving a solid or liquid drugin distilled water (aqua destillata) •Solutions are intended for topical, oral, and parenteraladministration. Solutions for local administration usuallycalled lotions.

Suspension (suspensio)•A suspension consists of a dispersion of relatively coarse particles, usually in aqueous vehicle.•Suspensions may be used fororal and topical administration.•Like solutions, oral suspensions areuseful in children and patients whocannot tolerate a solid dosage form.

Drops (guttae)

•Drops are solutions, tincturesor mixtures of high-potentdrug substances •Drops are prescribed in smallquantity (1030 g)

•Drops are intended to be administered orally or externally(as eye drops, nasal drops and ear drops).•eye drops (collyrium): Timolol •nasal (nose) drops: Olynth 0,1%•ear drops: Furotalgin

Emulsion (emulsio)Emulsions are two-phase systems consist of liquid drugsubstances. They are classfied as:• oil-in-water emulsion (O/W)• water- in-oil emulsion (W/O) Emulsions can be administered topically, orally, and I.M.

Liniment (linimentum)

•Liniments are milk-like liquids for topical administration.

•Example: Carmolis fluid Nival

Infusions and decoctions• Infusion (infusum) is a dilute solution of the readily soluble constituents of crude drugs (from the soft parts of plants).• Fresh infusions are prepared bymacerating the drugs for a shortperiod of time (15 min) withboiling water.

Decoction (decoctum)• Decoctions is an extract of thewater-soluble and heat-stableconstituents of crude drugs (from the hard parts of plants) by boilingin water for 30 min, and cooling.• Infusions and decoctions are ofshort duration (no more than 3 days).

Mixture (mixtura)Mixtures contain two or more active drug substance, dissolved, suspensed, or dispersed in a suitable liquid base. Syrups are added as remediumcorrigens, in quantity of 20 % or30 % of the total volume.Oral and topical administration

Medical nail lacquers•Such dosage form containsantifungal drugs for topicaltreatment of onychomycosis •Example: Batrafen nail lacquer 8 %Loceryl nail lacquer 8 %

Medical shampooSelected topical formulationsfor the treatment of seborrheicdermatitis are:•Nizoral shampoo•Selsun shampoo

Sterile dosage forms for injection

These forms contain solutions,powder or lyophilized powderready to be dissolve, suspensions,and emulsions. They are packaged in ampoules, vials, plastic bags, one-point cut ampoules, and prefilled disposable syringes.

10.a) Solutions can be prescribed in two forms (short or enlarged).•in short form the strength of a solution is expressed as the quantity of solute in sufficient solvent to make 100 ml (percentage strength) Rp/ Sol. Natrii citratis 4% 150 g D.S. Take 1 tablespoon 3 times daily.

•in enlarged form the total dose of the active substance, the name ofthe solvent, and the total volume of the solution are filled in praescriptio Rp/ Natrii citratis 6 g Aquae destillatae ad 150 g M.D.S. Take 1 tablespoon 3 times daily.M.D.S. = Misce. Da. Signa.

10.b)Rp/ Sol. Iodi spirituosae 5% 100 g D.S. For external use. 11.)Rp./Fl. Tussiroli 140 ml D. t .d. №1 S. Take 1 teaspoon 3 times daily. D.t.d. = Da tales doses

12.)Rp/ Infusi radicis Primulae 6 g/180 g Ephedrini hydrochloridi 300 mg Liquoris Ammonii anisati 3 g Natrii benzoatis 3 g Sirupi Althaeae ad 225 g M. f. mixtura D.S. Take 1 tablespoon 3 times daily.

12.) Calculation of the total dose of each drug of the mixture:•one tablespoon contains 15 ml (g)•the total number of doses is equalto the whole volume of mixture dividedby the volume of the one tablespoon: 225 g : 15 = 15•the total dose of each drug substance is equal to the total number of doses multiplied by the single dose of the drug

12.)•Ephedrini hydrochloridi single dose = 20 mg total dose = 15 x 20 mg = 300 mg•Liquoris Ammonii anisati single dose = 200 mg total dose = 15 x 200 mg = 3 g•Natrii benzoatis single dose = 200 mg total dose = 15 x 200 mg = 3 g

13a) Tinctura (T-ra)

Rp/ T-ra Valerianae 20 g D.S. Take 20 drops 3 times daily.

13.b) Drops

Rp/ Fl. Xylomethazolini 0,1% 10 ml D. t. d. №1 S. Put 2 drops into nose 4 times daily.

14.) Suspensions

Rp/ Fl. Cefuroxime 25 mg/5 ml D. t. d. № 1 S. Take 2 ml every 12 hours.

14.) Calculation of the single dose of Cefuroxime axetil for a childwith body weight 10 kg:

-- Daily dose = 10 mg x 10 kg = 100 mg-- The daily dose is divided by 2 equal applications: 100 mg/2 = 50 mg-- One ml (or 1 division) of suspension contains 25 mg of Cefuroxime or single dose = 100 mg/2 mg = 2 ml

15.) Infusions and decoctions

Rp/ Decocti fol. Uvae ursi 10 g/200 g D. S. Take 1 tablespoon 3 times daily.

16)

Rp/ Sol. Lydoli 5% 2 ml D. t. d. № 10 in amp. S. One ampule S.C.

Pethidine – INN (Lydol®) (Meperidine - USA)

17)

Rp/ Fl. Benzylpenicillini 500 000 UI D. t. d. № 20 S. One vial I.M. every 6 hours, after dissolving in 5 ml distilled water.

18a)Rp/ Fl. Fentanyli 0,005% 10 ml D. t. d. № 1 S. Injected 2 ml I.M.18b)Rp/ Fl. Droperidoli 0,25% 10 ml D. t. d. № 1 S. Injected 2 ml I.M.