What type of formulation typically contains therapeutic agents in a viscous base for application?

The formulation that typically contains therapeutic agents suspended or dissolved in a viscous base for application is an ointment. Ointments are designed to provide a protective barrier, enhance the delivery of the active ingredients, and prolong their therapeutic effect on the skin or other designated areas. The viscosity of the base in ointments helps to retain moisture and facilitates the absorption of the therapeutic agents, making them effective for localized treatments.

In comparison, creams generally have a lighter consistency and are emulsion-based, offering quick absorption for hydration without a significant oily residue. Gels are water-based and often provide a cooling effect upon application, but they do not typically have the same viscous base as ointments. Solutions are completely liquid formulations where the active ingredients are dissolved, lacking the thickness and protective qualities of ointments. Thus, the distinct characteristics of ointments make them particularly suitable for delivering and retaining therapeutic agents effectively.