JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD Pharm. D I Year PHARMACEUTICS Previous Question Paper (June/July - 2019 - R08)

A dosage form is the physical form of a dose of a chemical compound used as a drug or medication intended for administration or consumption. It is the means by which drug molecules are delivered to sites of action within the body.

Dosage forms are classified based on their physical state and route of administration:

• Solid dosage forms: Tablets, capsules, powders, granules, and pills.
• Liquid dosage forms: Monophasic (solutions, syrups, elixirs) and biphasic (emulsions, suspensions).
• Semi-solid dosage forms: Ointments, creams, pastes, gels, and suppositories.
• Gaseous dosage forms: Aerosols, inhalers, and sprays.

Posology is the branch of medical science that deals with the study of doses or the determination of suitable doses of drugs for patients.

The selection of an appropriate dose is influenced by several factors:

• Age: Infants and elderly patients often require lower doses due to differences in metabolism and excretion.
• Body weight: Doses are often calculated based on body surface area or weight (mg/kg) to ensure therapeutic efficacy.
• Sex: Physiological differences, such as hormonal variations and body composition, can influence drug response.
• Route of administration: Intravenous administration typically requires smaller doses than oral administration due to immediate bioavailability.
• Pathological state: Impairment of liver or kidney function necessitates dose adjustment to prevent toxicity.
• Tolerance and Idiosyncrasy: Repeated use may lead to tolerance (requiring higher doses), while idiosyncratic reactions are unpredictable individual sensitivities.
• Time of administration: Some drugs are better absorbed or tolerated at specific times of the day.