Recent advances in toxicological testing of the stratum corneum.

alpha-Hydroxy acid (AHA) formulations are commonly used for skin chemical peelings. The primary target is the stratum corneum (SC). The aim of this study was to assess the effects of various glycolic acid concentrations and commercial phenolic acid formulations on the SC. Quantitative colorimetry of a corneoxenometry bioassay was used. The test procedure involved glycolic acid concentrations ranging from 3% to 70% in alcoholic solution. Exposure times were set for 1 min and 3 min. The bioassay showed consistent reactivity with a dose-effect relationship when using the selected low exposure times. In a similar procedure the aggressiveness of commercially available phenolic acid formulations was identified not using hazardous in vivo testing. Corneoxenometry appears useful for in vitro testing of AHA peeling agents during short exposure times.