INTERACTION OF PERCUTANEOUS-ABSORPTION ENHANCER WITH STRATUM-CORNEUM OF HAMSTER-CHEEK POUCH - AN ELECTROPHYSIOLOGICAL STUDY

The effects of 1-dodecylazacycloheptan-2-one (Azone) and sodium lauryl sulfate (SLS) on the permeability to drugs of stratum corneum sheets (SC) isolated from hamster cheek pouch were investigated in vitro. By using an electrophysiological technique, the electrical resistance (R(m)) of the SC was determined by measuring its permeability to various drugs. It was shown that the isolated SC behaved as a lipid barrier to drug permeation and possessed high resistivity to ion flow. Pretreatment of the SC with SLS caused a marked decrease in R(m), indicating that its effect on drug permeability depends on its capacity to reduce the barrier function of the SC. On the other band, Azone enhanced mainly permeability to lipophilic drugs and did not result in significant change in R(m). It was suggested that Azone promoted drug permeation across the SC without reducing its role as a barrier to hydrophilic substances. The electrophysiological technique used in this study was believed to be useful for examining the interaction of some percutaneous absorption enhancers with SC.