Dosage Forms Of Drugs 2024-2025 PDF

GENERAL Pharmacology DOSAGE FORMS OF THE DRUGS by Dr. Khaled Abdelfattah Pharmacology department 2024-2025  LECTURE LEARNING OUTCOMES (LLOs)  By the end of this lecture the student should be able to:  Describe the different oral dosage forms of drugs ...

GENERAL Pharmacology DOSAGE FORMS OF THE DRUGS by Dr. Khaled Abdelfattah Pharmacology department 2024-2025  LECTURE LEARNING OUTCOMES (LLOs)  By the end of this lecture the student should be able to:  Describe the different oral dosage forms of drugs  Describe the rectal dosage forms of drugs  Describe the parenteral drug dosage forms  Describe the dosage forms of drugs administered by inhalation  Describe the topical dosage forms of drugs  ENTERAL DOSAGE FORMS A.ORAL DOSAGE FORMS: I.LIQUIDS: 1. SOLUTIONS: Aqueous solutions: i) Water: Aqueous solutions of volatile oils eg. Peppermint water. ii) Syrup: sugar saturated aqueous solution of the drug e.g cough syrups. iii) Aqueous extract: 100% concentrated drug extract in water. Alcoholic solutions: i) Spirit: Alcoholic solution of volatile oils. 3 ii. Elixir: sweetened hydroalcoholic solution of the drug eg. Antihistaminic elixir. iii. Tincture: 10-20% concentrated drug extract in alcohol. 2. Suspensions & Emulsions: Suspensions are insoluble solid substances in water. Emulsions are insoluble liquid substances suspended in water as oils with addition of an emulsifying agent as gum II. SOLIDS: 1.TABLETS: i) Ordinary tablet: A small disc of medicated compressed powder mixed with inert binder as starch or lactose. ii. Coated tablet: A sugar coat protects the drug and masks its bad taste. iii. Sustained release tablets: As spansules: different coats with different disintegration times to give rapid onset and long duration of action. 4 5 6 iv. Enteric coated tablet: The coat dissolves in the intestine to avoid gastric irritation. v. Subligual tablet: Friable for rapid buccal disintegration. vi. Lozenges: Flavored tablets which dissolve slowly when put in mouth. 2. CAPSULES: A drug enclosed in a gelatin capsule to avoid bad taste of the drug. i. Hard gelatin capsule: contain powder. ii. Soft gelatin capsule: contains fluid. iii. Spansule (sustained release capsule). iv. Enteric coated capsule to avoid gastric irritation. B. RECTAL: Liquid (Enema): I. Evacuant enema: Warm water 600 ml given rapidly under high pressure. II. Retention Enema: 100 ml given given slowly by drip under low pessure. 7 8 9 2. SOLID (SUPPOSITORY): The drug is incorporated in a waxy base. The evacuant enema and glycerin suppositories are intend ed to evacuate lower GIT while the retention enema and medicated suppositories are intended to administer drugs through the rectum eg.Corticosteroid enema in ulcerative colitis. Precautions before retension enema: 1. Rectum is first cleaned with evacuant enema. 2. Amount must not exceed 200 ml. 3. Level of solution must not be high. 4. Drug solution should not be irritant. PARENTERAL DOSAGE FORMS I. LIQUID (injections): 1. Ampoules. 2. Vials. The ampoule is a single dose of sterile solution. 10 11 12 13 The vial is a multidose preparation. Unstable drugs are prepared as vials to which the solvent is addes just before use. II. SOLID (implants): PELLETS. DRUGS GIVEN BY INHALATION: 1. GASES: Oxygen, Anesthetics. 2. VAPORS: i. Highly volatile eg. Amyl nitrite. ii. Not highly volatile eg. Tinct.Benzoin. 3. AEROSOL: suspension of liquid or solid in a gas. i. Nebulizer: Depends on the suction created by jet of air or oxygen to spray the drug. The amount of the drug delivered by the nebulizer is limit-ed only by the toxicity of the drug. ii. Inhaler: depends on the presence of a propellent substance added to the content of the inhaler. Thus the amount is limited by the toxicity of the drug as well as the additives included in the inhaler. 14 15 16 The use of the inhaler needs an intelligent cooperative patient. iii. Spinhaler is used for solid aerosol. SKIN DOSAGE FORMS: I. LIQUIDS: 1.Lotion:aqueous solution for local application. II. Liniment: alcoholic solution for local application. 2. SEMILIQUID: I. Cream:Emulsion of oil in water eg.Corticosteroid cream II. Ointment: Emulsion of water in oil (80% oil) eg. Corticosteroid ointment. N.B. The ointment is used for dry lesions while the cream for semiwet lesions and the lotions for wet lesions. 17 18 19 3. SEMISOLID: I. Paste: mixture of powder + ointment. II. Patches: A patch containing the drug eg. Nitroglycerin. 4. SOLID: powder eg. Antifungal powder. 20