ABSTRACT
The skin is the largest organ of human body. It has long been considered a prime site for drug administration for diseases of skin or other organs. It is known that the biochemical order of intercellular lipid matrices of the stratum corneum must be altered to increase the penetration of compounds. However, an ideal skin permeation enhancer should specifically promote penetration of drugs across the skin barrier without permanently changing its properties. This chapter describes the three most common approaches for enhancing skin permeation. The first approach utilizes physical forces, such as electricity and ultrasound, to alter skin permeability or increase thermodynamic activity to enhance skin absorption. The second approach incorporates chemical enhancers into delivery systems to reduce skin resistance or modify drug molecules to improve the partition coefficient and/or diffusivity within the stratum corneum. The third approach integrates drug molecules into vehicle carriers, such as lipid micelles, liposomes, and Transfersomes to facilitate deposition of the drugs into the skin.
