AN ELECTRON-SPIN-RESONANCE STUDY OF HUMAN EPIDERMAL LIPIDS USING 5-DOXYL STEARIC-ACID

The effect of laurocapram (1-dodecylazacycloheptan-2-one, Azone(R)) on the lipids of human epidermis was studied by electron spin resonance (ESR) of 5-doxyl stearic acid (5-DSA) intercalated into the epidermis. Order parameters S, polarities a(0) and S/W ratio (strongly immobiliz ed/weakly immobilized spin label) from the ESR spectra demonstrate tha t Azone(R) increased the fluidity and the polarity of the local enviro nment surrounding the spin label, and modified the conformation of epi dermal lipid, Skin recovery from the disordered system was observed at a low Azone(R) concentration. Comparatively, Azone(R) showed a greate r effect on stratum corneum lipid bilayers and a smaller effect on epi dermal lipids. There was no direct relationship between the amount of enhancer used and the ESR parameters.