Different modes of the effect of 1, 2-propanediol and azone on stratum corneum lipids

The stratum corneum (SC) controls the diffusion and penetration of drugs into and through the skin. In this investigation, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were used to study the effect of two enhancers, 1,2 propanediol and azone, on lipids extracted from SC (SC lipids). The two enhancers affected the SC lipids. However, their function modes were different. The penetration enhancing mechanisms of the two enhancers are discussed based on their effects on SC lipids and on their efficiencies in arbutin permeation enhancement. 