Which type of pharmaceutical formulation is specifically designed for use on the skin?

Topical formulations are specifically designed for application on the skin or mucous membranes. They deliver medication directly to the target area, allowing for localized treatment and minimizing systemic absorption. These formulations can come in various forms, including creams, ointments, gels, and lotions, making them versatile for various dermatological conditions.

In contrast, aqueous solutions for injection are intended for parenteral use, meaning they are designed to be injected, not applied externally to the skin. Aerosol-nebulizers are primarily used for respiratory delivery, targeting the lungs rather than the skin. Enteric-coated formulations are designed to withstand gastric acid and dissolve in the intestines, serving a specific purpose for gastrointestinal absorption rather than topical application.

Therefore, the topical formulation is the correct answer, as it aligns with the requirement of being specifically designed for use on the skin.