Improved drug delivery using microemulsions: Rationale, recent progress, and new horizons

Microemulsions are excellent candidates as potential drug delivery systems because of their improved drug solubilization, long shelf life, and ease of preparation and administration. The formulation of microemulsions for phar maceutical use requires a thorough understanding of the properties, uses, a nd limitations of microemulsions. Three distinct microemulsions-oil externa l, water external, and middle phase-can be used for drug delivery, dependin g upon the type ui drug and the site of action. In this article, we present an examination of microemulsions as drug carrier systems, starting with ge neral information and moving to a thorough review of the microemulsion lite rature, with a special section devoted to microemulsion-based gels.