Transdermal and Topical Drug Delivery Systems

Abstract

Transdermal drug delivery development was mostly carried out in 1980 to 1995 as indicated by the number of patents awarded and products that entered interstate commerce. Topical delivery systems represent formulations that are intended to deliver drugs locally rather than systemically to treat local pathophysiologic conditions. For oral and parenteral drugs with very short biological half-lives and high body clearance rates, frequent dosing is required to elicit and maintain a pharmacological effect. A suitable size of heat-separated human epidermis is die cut and mounted between the two halves of the Franz cell, with the stratum corneum side facing the transdermal drug delivery system. Transdermal delivery avoids the erratic drug absorption through the gastrointestinal tract, as it bypasses the hepatic clearance by delivering the drug directly into the systemic circulation. A drug could have all the physicochemical properties that are essential to be a good transdermal candidate but elicit a powerful toxic response.