PharmDecks

Dermatology and Wound Management

Introduction

Topical formulations are applied directly to the skin.

  • Advantages:
    • Deliver higher drug concentration at the target site.
    • Fewer systemic side effects.
  • Disadvantages:
    • Can be messy or time-consuming.
    • May require multiple applications or products.

Each formulation contains an active ingredient (e.g., corticosteroid, antifungal) and a vehicle/base (e.g., cream, ointment, gel) designed to deliver the drug effectively.


Types of Formulations

Formulation Key Features Best For
Creams Oil-in-water emulsions (approx. 50/50). Moisturising. Require preservatives. Normal to dry skin
Ointments Greasy, semi-solid, occlusive (80% oil), water-free. No preservatives needed. Dry, scaly skin
Gels Aqueous/alcoholic, often cellulose-based. Liquefy on contact. May contain preservatives/fragrances. Oily/combination skin
Lotions Thicker than solutions, lighter than creams. Often water-based. Oily skin, warm climates
Patches Adhesive systems for systemic drug delivery. Bypass first-pass metabolism. Long-term, precise dosing

Active Ingredients (Selected Examples)

Category Purpose Examples
Corticosteroids Inflammation, itching (eczema, dermatitis) Hydrocortisone, Clobetasol, Triamcinolone
Antifungals Tinea, candidiasis, fungal infections Clotrimazole, Terbinafine, Nystatin
Antibacterials Impetigo, folliculitis, cellulitis Mupirocin, Polymyxin B, Bacitracin
Keratolytics Exfoliation, acne, wart removal Salicylic acid, Glycolic acid, Lactic acid, Podophyllotoxin

Choosing the Right Formulation

Based on Skin Type

Skin Type Recommended Formulation Ingredients to Look For
Oily Lightweight gels, water-based lotions Hyaluronic acid, Glycerin
Dry Thick creams, ointments Shea butter, Ceramides, Urea
Sensitive Hypoallergenic, fragrance-free creams Aloe vera, Oatmeal
Normal Light non-greasy moisturisers Balanced humectants/emollients
Combination Gel/lotion hybrids or mix by area Varies

Based on Skin Condition

Condition Type Suggested Formulation
Wet/oozing lesions Creams, lotions, drying pastes
Dry/scaly skin Ointments, oils
Inflamed skin Soaks → creams/ointments
Cracked/sore skin Bland preparations
Palms/soles Creams or ointments
Hairy areas Gels, foams, solutions
Skin folds Creams or lotions (not ointments)
Mucosal areas Non-irritating formulations

Key Pharmacological Considerations

Factors Influencing Absorption:

  • Skin thickness: Thinner = greater absorption

  • Barrier integrity: Damaged skin absorbs more

  • Occlusion: Increases drug penetration

  • Lipophilicity & molecule size

  • Concentration & excipients

Special Populations:

  • Babies: Fragile barrier, immature organs — use with caution

  • Pregnancy/Breastfeeding: Avoid potentially teratogenic topicals (e.g., Podophyllin, 5-FU, high-strength salicylic acid)

Application Tip:

  • For best results, apply topicals to damp skin (within 3 minutes of bathing) to improve absorption and hydration.


Common Ingredients in Vehicles

  • Occlusives: Petrolatum, mineral oil (seal in moisture)

  • Humectants: Hyaluronic acid, glycerin (draw moisture in)

  • Emollients: Ceramides, shea butter (soothe and smooth)

  • Preservatives: Prevent bacterial/fungal growth

  • Enhancers: Propylene glycol, alcohol — may aid penetration


Summary

  • Choose formulation based on skin type, condition, location, and patient preference.
  • Know when to use emollient-rich ointments vs. lightweight lotions or gels.
  • Topical corticosteroids are potent anti-inflammatory agents — use appropriate potency and avoid long-term use.
  • Tailor treatment and base formulation to maximise therapeutic benefit while minimising irritation.

References

0% Complete