Interactions of C12 surfactants with the skin: studies on enzyme release and percutaneous absorption in vitro.

Using an in vitro penetration cell, it has been shown that enzymes (acid phosphatase, lactate dehydrogenase and N-acetylglucosaminidase) are released from rat-skin slices in response to contact with two irritant C12 surfactants, sodium laurate and sodium lauryl sulphate, but not with the non-irritant sodium lauroyl isethionate. About 3-5 hr contact of the stratum corneum with surfactant and a long incubation time (24 hr) were required for enzyme release. Adsorption and penetration of the two effective surfactants was also studied and the results for sodium lauryl sulphate suggested a relationship between enzyme release and adsorption of surfactant. However, no such simple relationship was observed for sodium laurate, emphasizing the complex nature of surfactant interactions with the skin.