Ointment Suppositories

1. Topical Preparations

  • Definition: Preparations applied to the skin for physical or medicinal effects.

  • Types: Protectants, lubricants, emollients, drying agents.

  • Common forms: Ointments, creams, gels.

2. Transdermal Systems

  • Purpose: Designed to allow drug substances to pass through skin layers and into systemic circulation.

3. Functions of Dermatologicals

  • Protection: Shields injured areas from environmental factors.

  • Hydration: Provides skin hydration (emollient effect).

  • Medication transport: Serves as a vehicle for delivering medication.

4. Skin Structure

4.1. Epidermis

  • Function: A waterproof barrier protecting against pathogens.

4.2. Dermis

  • Components: Connective tissues, fibroblasts, collagen, hair follicles, and sweat glands.

4.3. Hypodermis

  • Role: Acts as padding against shock and provides energy reserves.

5. Histological Divisions of the Skin

  • Horny Layer (Stratum): Outermost layer.

  • Barrier Layer (Living Epidermis): Provides protection and function.

  • Dermis: The true skin layer containing structures vital for function.

6. Drug Penetration Factors

  • Influencing factors include:

    • Pressure and vigor of application.

    • Surface area of skin covered.

    • Condition of the skin.

    • Base used for the formulation.

    • Use of occlusive dressings.

7. Mechanisms of Drug Permeation

  • Pathways:

    • Transcellular: Through individual cells.

    • Intercellular: Between cells of the horny layer.

    • Transappendageal: Through hair follicles and glands.

8. Percutaneous Absorption

  • Definition: Absorption of substances through the skin into underlying layers and into the bloodstream.

  • Factors affecting absorption include skin hydration, occlusion, and time of exposure.

9. Types of Dosage Forms

9.1. Ointments

  • Characteristics: Semisolid, external application, can be medicated or non-medicated.

  • Base types include:

    1. Oleaginous bases: Excellent emollients but less cosmetically appealing.

    2. Absorption bases: Can absorb water, providing emollient properties.

    3. Water-removable bases: O/W emulsions, easily washed off.

    4. Water-soluble bases: Greaseless and completely water washable.

9.2. Creams

  • Definition: Opaque, semisolid preparations typically mixed in water-soluble bases.

  • Types: O/W creams (foundation, shaving) and W/O creams (cold creams, emollients).

9.3. Gels

  • Composition: Dispersions in an aqueous liquid, can be single-phase (homogeneous) or two-phase (particulate).

  • Common uses: Variability in absorption and physical properties.

9.4. Transdermal Preparations

  • Components: Often contain penetration enhancers to improve absorption through the skin.

9.5. Pastes

  • Characteristics: Stiffer due to high solid content, suitable for certain skin areas but not for hairy parts.

9.6. Plasters

  • Use: Provide prolonged contact at application sites for local effects.

10. Suppositories

  • Definition: Solid dosage forms for insertion into body orifices to exert local or systemic effects.

  • Ideal Characteristics include:

    1. Melts at body temperature.

    2. Non-toxic, compatible with other medicaments.

    3. Stable during use and storage.

10.1. Types of Suppositories

  • Rectal Suppositories: Used for local action, commonly for constipation relief or anti-inflammatory agents.

  • Vaginal Suppositories: Designed for local use, including contraceptives and antifungals.

  • Urethral Suppositories: Less common, used for local anesthetics or antibacterial purposes.

11. Preparation Techniques for Suppositories

  • Common methods:

    • Molding/Fusion: Melting base and mixing with medicament.

    • Cold Compression: For heat-sensitive medicaments.

12. Absorption Factors for Suppositories

  • Physiological factors: Colonic content, circulation route, skin pH.

  • Physicochemical factors: Particle size, solubility, and base nature.

13. Packaging and Storage Recommendations

  • Glass or plastic containers for moisture control.

  • Chocolate-like solid consistency for cocoa butter; must be cooled and stored appropriately to maintain integrity.