Dosage Forms of Drugs PDF

Dosage Forms of Drugs  Dosage Forms of Drugs: is the form in which the drug is administered to the patient Enteral 1- Oral 3- Rectal 2- Buccal...

Dosage Forms of Drugs  Dosage Forms of Drugs: is the form in which the drug is administered to the patient Enteral 1- Oral 3- Rectal 2- Buccal 4- Gastric gavage Parental 1- Injection 2- Subcutaneous implantation Inhalation Topical  I) Enteral 1- Oral dosage forms 1.1. Solids A) Tablets: A tablet is a solid dosage form of varying weight, size and shape in which the drug is compressed with pharmacologically inert substances  Types of tablets: 1- Simple tablet : a small disc of medicated compressed powder mixed with inert binders as starch or lactose e.g. aspirin. 2- Coated tablet: a sugar coat protects the drug & masks its bad taste 3- Enteric-coated tablet: the coat dissolves in the intestine (alkaline PH) to avoid gastric irritation or inactivation 4- Chewable tablets. 5- Effervescent tablets e.g. vitamin C tablets.  B) Capsules: These are gelatin shells containing individual doses of drugs in a tasteless form to avoid bad taste of drug. Types of capsules: 1- Hard gelatin capsule: contains powder 2- Soft gelatin capsule: contains liquid 3- Spansule (sustained- release capsule) C) Powders: A powder form of drugs may be dispensed in small paper packets and may be formulated as effervescent granules. Effervescent is prepared by adding sodium bicarbonate + tartaric or citric acid to the drug, when added to water CO2 release which masks the salty or bitter taste of the drug.  1.2. liquids A) Solutions: Aqueous solutions Non-aqueous solutions Liquid preparations that contain one or solutions which contain solvents more soluble chemical substances other than water, either alone or in dissolved in water. addition to water Examples: Examples: 1-Aromatic Water: Aqueous solution 1- Elixir: alcohol + sugar + water of volatile oil such as Peppermint 2- Spirit: Volatile oil in alcohol Water e.g. peppermint spirit. 2- Syrup: Concentrated aqueous 3- Tincture: Alcoholic preparation solution of sugar containing active of vegetable drugs substances  1.2. liquids B) Suspension A preparation of insoluble solid drugs suspended in an aqueous vehicle. Must be shaked before use. C) Emuslion Emulsion is a mixture of two immiscible liquids, such as oil and water, where one liquid is dispersed in the form of small droplets within the other liquid. It is stabilized by the addition of an emulsifying agent.  2- Buccal dosage forms Dosage forms that are introduced into the mouth but not swallowed. 1- Sublingual tablets: tablet placed under the tongue for rapid buccal disintegration e.g. nitroglycerine for angina. 2- Lozenges: Flavored tablet which dissolves slowly in the mouth. 3- Mouth wash, gargle, paint and gel.  3- Rectal dosage forms 3.1. Liquid (Enema) Evacuant enema Retention enema Intended to evacuate the To administer drug through rectum e.g.: lower GIT. corticosteroid in ulcerative colitis 3.2. Solid (Suppository) 1. Glycerin suppository: to evacuate the lower GIT. 2. Medicated suppository: to administer drugs through rectum  II) Parenteral Dosage form 1- Liquid (injection) 1- Ampoule: a single dose of sterile solution or suspension. 2- Vial: rubber-capped glass. It may be single dose or multi-dose preparation. Unstable drugs are prepared as vials to which the solvent is added before use. 3- Bottles: used when large amount of drugs are needed as glucose or saline. 4- Insulin pen injector: contains cartridge of insulin and replaceable needles. 2- Solid (implants) Pellets  III) Inhalation Dosage form A- Gases: Oxygen and some general anesthetics. B- Vapors: Highly-volatile liquids e.g. halothane (general anesthetic). C- Systemic inhalation: Drugs vaporized by steaming. D- Aerosols: suspensions of a liquid or solid in a gas administered through: Nebulizer or Metered-Dose inhalers E- Powders: are administered through Spinhalers  IV) Topical Dosage form 1- For local effect on mucous membranes and skin Mucous membranes A- Eye B- Ear C- Vagina D- Nose Skin 1- Ointment: a fatty base (vaseline) immiscible with water. 2- Cream: is prepared from a base which is miscible with water. 3- Gel: It is solid or semisolid in cold and become liquid with warming. 4- Lotions: aqueous preparations that are applied to the skin without rubbing e.g. calamine lotion 5- Dusting powder: a powder applied to the skin for protective effect e.g. talc powder or for therapeutic effect e.g. antifungal 2- For systemic effect e.g. transdermal patch (nitroglycerine patch). Quiz :True or false: 1. Enteric coated capsule is used to avoid gastric irritation. 2. Hard gelatin capsule contains liquid. 3. Soft gelatin contains powder. 4. A vial is a rubber capped glass preparation for parentral administration. 5. An ampoule is a single dose preparation for parentral administration. 6. Spinhaler is used for liquid aerosols. 7. Enteric coated tablets dissolve in the stomach. 8. Sublingual preparations have rapid onset of action and by pass liver metabolism. 9. Sugar coated tablets are used to avoid bad taste of the drug. 10.Parentral preparations must be sterile and pyrogen free.