Penetration Enhancers and the Percutaneous Absorption of Drugs: An Update

Abstract

Dermatological preparations may be formulated for optimal bioavailability by ensuring that the drug has maximum tendency to leave the vehicle and pass into the skin. Alternatively, compounds (penetration enhancers, accelerants, or sorption promoters) may be included in the formulation that themselves pass into the skin and in so doing reversibly decrease its resistance to drug passage. The literature on penetration enhancers to 1981 was comprehensively reviewed by Barry. This paper discusses work performed since that time, with special reference to glycols, sulfoxides, amides and amines, pyrrolidones, and Azone. These and other compounds continue to be investigated as penetration enhancers for both local and systemic delivery of drugs. An important future role lies in their incorporation into transdermal delivery systems.