Cumulative effect of surfactants on cutaneous horny layers: lysosomal activity of human keratin layers in vivo.

Anionic surfactants have various degrees of membrane labilizing action on isolated lysosome in vitro. This action has been found to correlate with the degrees of skin roughness induced by the surfactants using the circulation method applied to the forearm of human subjects. It has been shown that the acid phosphatase activity in the human horny layer decreases during the in vivo application of the surfactants by the circulation method. The magnitude of the decrease in acid phosphatase activity has been found to correlate to the degree of skin roughness and to in vitro lysosome labilization induced by the surfactants.