Effect of Penetration Enhancers on Transdermal Absorption of Insulin Across Human Cadaver Skin

Abstract

The transdermal diffusion of insulin, a model polypeptide drug, across the human cadaver skin (HCS) was evaluated in vitro, in presence of penetration enhancing solvents, anionic surfactants, biosurfactants, a natural moisturizing agent and combinations thereof. Also, an attempt was made to relate the enhanced penetration to physical parameters like distribution coefficient, surface tension and viscosity. The results of the permeation experiments indicate that the permeation enhancers used in the present investigation significantly enhance the amount of drug entering into the HCS and the amount reaching to the skin. A synergistic effect on permeation enhancement was observed in cases where combination of permeation enhancers were selectively used. Reasons for this synergism were critically examined and established.