3rd-year class Practical Pharmacology 2010-2011 Lab.2 3rd-year class Practical Pharmacology 2010-2011

Dosage Forms Dr. Mohammed Qasim & Dr. Huda Ibrahim

I.Oral 1.Tablets:- the most common preparation for oral use . Is made by compressing the drugs & inert binders as starch or lactose into hard mass which disintegrate in water . A tablet before being absorbed should disintegrate into granules& then dissolute into primary drug particles

The active substance in an oral solid dosage form such as tablet represents only a small proportion of the total weight . These include:- diluents(Lactose, Calcium, Sulphate), binding agents(bentonile), lubricants(talc), disintegrating agents (starch , mixture of sodium bicarbonate & tartaric acid), coating formulation . material (sugar), special Different manufacturing procedures may result in the production of different physical forms of the active drug(e.g. compression force & tablet hardness).

Coated tablets:- a common type is a sugar coated tablet Coated tablets:- a common type is a sugar coated tablet. The coat is an additional physical barrier for disintegration. 1-Coatings are used to mask the unpleasant tastes & odors. 2-To protect the tablet ingredients from decomposition in drug storage. 3-To improve the appearance of the tablet

Enteric-coated tablet:- a special film coat designed to resist gastric fluid & disrupt or dissolve in the intestine 1-They are used to protect a drug from degradation in the stomach. 2-To minimize gastric irritation caused by some drugs

Sustained-release tablets(SR) this is designed to release their contents over extended period of time.

Advantages: to eliminate the need for multiple dosage regimens , particularly for these drugs requiring reasonably constant blood level over a long period of time , or drugs which need to be given in high doses , but too rapid release is likely to cause undesirable side effect (e.g. potassium chloride tablets)

2.Capsules:- a drug formulation encapsulated in a hard gelatin shell .Drug particles in the capsule are not subjected to high compression that tend to compact the powder & to reduce the effective surface area. However, drug bioavailability from capsule isn't always better than a tablet.

Advantages: 1.Protection from light. 2. Mask the taste or odour of their components. 3. Attractive appearance. 4. Ease to identify. 5. Controlled release.

Spansule: capsule containing drug granules with special pharmaceutical formulation to be disintegrated and dissolved in different times for prolonged action (theophyllin)

3.Granules:- all irregular particles of drug, sugar & inert adjuvant stirred in water before taking

4.Effervescents tablet or granules:- the basis of the effervescence is a mixture of citric acid & tartaric acid with sodium bicarbonate . When dissolve in water , the acid & bicarbonate react together to produce carbonic acid . The carbonated water partly disguises the unpleasant taste of drug & has refreshing properties.

5.Syrup:- is a concentrated aqueous solution of sugar , useful vehicle for water soluble drugs act both as a solvent & flavoring agent . Advantages: 1. Immediately available for absorption. 2. Useful for children or in swallow difficulties (elderly).

6.Elixir:- is a sweetened hydro alcoholic solution that contains approximately 25%. It is a suitable vehicle for drugs soluble in either water or dilute alcohol.

7.Linctuses:- are viscous liquid oral preparations that are usefully prescribed for the relief of cough

II.Topical:- 1.Aerosols:- they are suspensions of fine solid or liquid particles in a gas . They are used to the respiratory tract or skin . The sprays used to treat respiratory diseases are atomized in devices known as nebulizers

2.Gargles:- they are aqueous solutions used to treat or prevent throat infections, usually dispensed in concentrated form to be diluted in warm water before use

3.Drops:- could be to the eye, ear, nasal or oral drops. Nasal drops are usually aqueous because oily drops inhibit movement of cilia in the nasal mucosa & if used for a long time , they may reach the lungs & cause lipoidal pneumonia

4.Ointments:- are semisolid, greasy preparations for application to the skin , rectum . The base is usually anhydrous & contains the medicament in solution or suspension. 5.Cream:- they are semisolid solution for external use. They are 2 kinds:-1. aqueous cream 2. oily cream. In which the emulsions are oil in water or water in oil respectively

Ointment Cream 1-greasy 1-relatively not greasy 2-semisolid anhydrous 2-semisoilid emulsion(oil + water) 3-less skin penetration 3-more skin penetration 4-used for dry, chronic skin lesion 4-used for wet lesions of skin 5-applid to skin & rectum Applied to skin only

6.Lotions:- aqueous preparations for external application without friction . They are rubbed on skin or applied on the suitable dressing

7.Suppositories:- are conical or ovoid solid preparations for insertion into the rectum, where they exert local or less often systemic effect. Their base is fat, wax or glycerol gelatin

8.Pessaries:- solid medicated preparations for introduction into vagina where they melt or dissolve & exert a local action

III.Injections:- drugs given by injections act more rapidly & reliably, thus more useful for emergency situations . They require some technical skills, aseptic technique & suitable equipments

a. Injection: highly purified & sterile dosage form either in ampoules or vials (for multidose) . b. Intravenous Admixture: (i.v. fluid) large volume injection intended to be administered by i.v. infusion , for fluid replacement ; electrolytes balance restoration; supplementary nutrition; & as vehicle for other drug substance (G/W, Albumin, Dopamine).

There are 2 types of injections preparation:- 1-Ampoule:- which contains sterile drug solution & used once when opened. 2-Vial:- which is designed to contain one or multiple doses & having a rubber cover to avoid contamination.  

IV.Some pharmaceutical preparations:- 1.Extract:- are concentrated preparations containing active principles of vegetable or animal drugs. The drugs are extracted with suitable solvents & the product is concentrated to a liquid, soft or dry extract. 2.Tinctures:- are alcoholic or hydro alcoholic solution of the active principles of drugs. They are medicated or non-medicated. The latter is used as flavoring agent. 3.Waters:- aromatic waters are saturated aqueous solutions of volatile oils, used as vehicle for water-soluble substances

Enema: a clyster or injection; a liquid injected or to be injected into the rectum (e.g. hydrocortisone enema), & barium enema (barium meal). Powder:e.g. antacid. Prefilled syringe: e.g.enoxaparn. Pen: e.g. mixtard insulin

Transdermal delivery system (TDS):