ABSTRACT
The topical/transdermal (TT) delivery route for drug administration has many advantages over other pathways, including avoiding the hepatic first-pass effect, continuous drug delivery, fewer side effects, and improved patient compliance (1). A major obstacle to TT drug delivery is the low penetration of drugs through skin. The stratum corneum (SC) provides a principal barrier to TT delivery of applied drugs and consists of corneocytes that are embedded in an intercellular lipid matrix composed of ceramides, free fatty acids, and cholesterol (CHOL) (2). Several approaches have been used to weaken this skin barrier and to improve TT drug delivery (3-8).
