1. Ointments

Definition & use
Ointments consist primarily of greasy bases (such as Vaseline or Lanolin) and contain little to no water. They are applied directly to the skin to deliver drugs locally.

Advantages

• Provide strong occlusive effects
• Enhance drug penetration through the skin
• Suitable for dry or chronic skin conditions

Limitations

• Greasy texture may reduce patient acceptance
• Difficult to wash off

Example
Mupirocin Ointment 2% (Bactroban®) – used to treat bacterial skin infections such as impetigo.

Bepanthen Ointment - used for dry, cracked skin or diaper rash.

2. Creams

Definition & use
Creams are semi-solid emulsions, usually oil-in-water (O/W), that are easy to spread and cosmetically acceptable. They are commonly used for inflammatory or fungal skin conditions.

Advantages

• Less greasy than ointments
• Better patient comfort and acceptance

Limitations

• Less occlusive
• Require preservatives due to water content

Example
Clotrimazole Cream 1% (Canesten®) – used for fungal skin infections.

3. Gels

Definition & use
Gels are semi-solid systems in which the drug is dispersed in a polymeric network. They are usually transparent, non-greasy, and quickly absorbed.

Advantages

• Cooling and soothing effect
• Suitable for oily skin and hairy areas

Limitations

• Limited drug-loading capacity
• May cause skin dryness with prolonged use

Example
Diclofenac Sodium Gel 1% (Voltaren® Gel) – used for local pain and inflammation.

4. Pastes

Definition & use
Pastes are stiff semi-solid preparations containing a high proportion of solid particles. They provide a protective effect and remain at the site of application for a longer time.

Advantages

• Protective and absorbent
• Minimize skin irritation

Limitations

• Difficult to spread
• Less cosmetically appealing

Example
Zinc Oxide Paste – commonly used for diaper rash and skin protection.

Conclusion

Semi-solid dosage forms are essential in topical drug therapy. Each type—ointment, cream, gel, or paste—has distinct properties that influence drug absorption, patient comfort, and therapeutic effectiveness. Understanding these differences helps pharmacy students and healthcare professionals choose the most appropriate formulation for each clinical situation.

Key Terms