In vitro effect of penetration enhancers on sodium nonivamide acetate in rat skin.

Sodium nonivamide acetate (SNA) is a newly synthetic analogue of capsaicin which produces no overt pungent sensation or irritation. In this present study, the effects and roles of penetration enhancers for SNA through rat skin were investigated by in vitro skin penetration experiment and differential scanning calorimeter (DSC) determination. The penetration fluxes of SNA after the incorporation of enhancers increased in the order of Polysorbate 20 < sodium laurylsulfate < or = benzalkonium chloride. This result was consistent with that of DSC profiles which indicated the disruptive effects of surfactants on the rat stratum corneum increased in the order of Polysorbate 20 < sodium laurylsulfate < benzalkonium chloride. The information gained is particularly helpful in the development of SNA transdermal drug delivery system.