Pharmaceutical dosage forms are the physical forms in which drugs are produced and delivered to patients. They make drug administration safe, effective, and convenient. A dosage form ensures the correct dose reaches the right site in the body at the right time. Examples include tablets, capsules, injections, creams, and syrups.
Need for Dosage Forms
- Ensure safe and accurate dosing
- Improve patient convenience and compliance
- Protect drug from environmental factors such as light, air, and moisture
- Mask unpleasant taste or odor of drugs
- Enable controlled or targeted drug release
- Facilitate drug absorption
- Provide stability to unstable drugs
Ideal Characteristics of a Dosage Form
- Safe and effective
- Acceptable to the patient
- Stable during storage
- Easy to manufacture and transport
- Delivers drug at a predictable rate
- Economical
Classification of Pharmaceutical Dosage Forms
Dosage forms are classified based on their physical form, route of administration, and drug release characteristics.
1. Based on Physical State
(A) Solid Dosage Forms
- Tablets
- Capsules
- Powders
- Granules
- Suppositories
(B) Liquid Dosage Forms
- Solutions
- Suspensions
- Emulsions
- Syrups
- Elixirs
(C) Semi-Solid Dosage Forms
- Ointments
- Creams
- Gels
- Pastes
(D) Gas or Aerosol Dosage Forms
- Inhalers
- Aerosol sprays
- Nebulizer solutions
2. Based on Route of Administration
Oral Route
- Tablets
- Capsules
- Liquids (syrups, elixirs)
Parenteral Route
- Injectables (IV, IM, SC)
Topical Route
- Creams, ointments, lotions
- Patches
Ophthalmic Route
- Eye drops
- Eye ointments
Inhalation Route
- Dry powder inhalers
- Metered-dose inhalers
Rectal and Vaginal Route
- Suppositories
- Pessaries
3. Based on Drug Release Characteristics
Immediate Release
Drug is released rapidly after administration.
Modified Release
- Sustained release: Releases drug over a prolonged period
- Controlled release: Maintains constant drug levels
- Delayed release: Releases drug after a specific time or at specific site (e.g., enteric-coated tablets)
Examples of Dosage Forms and Their Uses
- Tablets: Most common, easy to use and stable
- Capsules: Suitable for powders and oily drugs
- Syrups: Ideal for children and elderly
- Injections: For rapid action or when oral route is not feasible
- Creams/Ointments: For localized skin conditions
- Inhalers: For asthma and respiratory diseases
Factors Influencing Selection of Dosage Forms
- Nature of the drug (stability, solubility)
- Desired onset of action
- Patient age and condition
- Route of administration
- Target site in the body
Detailed Notes:
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