Today's cosmetic emulsions are not simply mixtures of oil, water and emulsifier; they also contain a number of active ingredients functioning to ameliorate the condition of the skin, such as skin hydration or the barrier properties of the stractum corneum (SC). Most of these ingredients will work only if they penetrate the SC or the deeper layers of the epidermis. The extent and rate of penetration depend not only on the diffusion and solubility properties of the ingredietn molecule itself, but also on the effect of the cosmetic vehicle of the diffusion process.
Excerpt Only This is a shortened version or summary of the article that appeared in the Dec. 1, 1997 issue of Cosmetics & Toiletries magazine. The full content is not currently available online.