Ascorbic acid on collagen: Garcia- Mercier investigated the effect of a w/o emulsion containing ascorbic acid on collagen neosynthesis in human full thickness skin discs in culture. The response of human skin disks to agents having the ability to increase collagen synthesis was investigated. Seven experiments were performed, each using skin disks obtained from female patients. L-ascorbic acid in the culture medium was incubated with skin for 72 hours. Collagen synthesis was evaluated by measuring 3H-proline incorporation into dermis proteins. Expected effects were found and results were shown to be reproducible. Two cosmetic formulations – a clear solution and a w/o emulsion containing L-ascorbic acid – were then tested by topical application on the human skin disks and incubated for 72 hours.
The w/o emulsion increased collagen neosynthesis whereas the solution was without effect. In my view, these results, while representing an isolated case study, points to the importance of the vehicle in determining the physiological effects of actives on the skin. Skin cleansing sheets: Shiseido discloses skin cleansing sheets containing anionic surfactants and polyoxyalkylenes. 2 The sheets contain cleansing compositions utilizing anionic surfactants and propoxylated/ethoxylated polyols containing 2-100 moles of propylene oxide and 0 - 50 moles of ethylene oxide. The compositions show good foaming, makeup and sebum removal, and skin moisturizing effect. A cleansing sheet was prepared from a rayon-polyester nonwoven fabric impregnated with a surfactant composition shown in Formula 1.