Which dosage forms are used for medicines delivered through the skin?

Medicines delivered through the skin are formulated in a variety of dosage forms, ranging from simple solutions to more complex delivery systems, depending on whether the intended effect is localized or systemic.1

Common dosage forms include:

• Semisolid preparations: These include ointments, which typically have a greasy or oily consistency often based on petroleum jelly, and creams, which are similar to ointments but often utilize water-in-oil emulsions to provide a softer, more spreadable texture.12
• Powders: These are used for topical application depending on the specific skin condition being treated.1
• Transdermal delivery systems: These are specialized structures designed for systemic drug administration. Examples include impregnated disks (such as those used for nitroglycerin) and polymer devices (such as those used for scopolamine).1
• Solutions: Simple liquid formulations may also be used as vehicles for topical drug application.1

The choice of formulation is determined by the nature of the skin lesion or the desired pharmacological action, such as anti-inflammatory, antibacterial, or analgesic effects.1