EFFECTS OF VITAMIN-E AND SQUALENE ON SKIN IRRITATION OF A TRANSDERMAL ABSORPTION ENHANCER, LAUROYLSARCOSINE

Alleviators of skin irritation were sought and their practical usefulness was evaluated in rats during the development of reaction to lauroylsarcosine (LS), an enhancer of transdermal absorption. LS (0.04-5%) produced erythema in a dose-related manner. Microscopic findings suggested that the damage by LS on keratinocytes caused this skin irritation. In a cultured fibroblast model, vitamin E and squalene were screened as reducers of LS-induced cell damage. Both compounds apparently alleviated 1% LS-induced erythema. Moreover, the combined addition of vitamin E or squalene and LS to isosorbide dinitrate (ISDN) ointment maintained greater penetration and less irritation.