In Brief: AHA skin penetration

AHA skin penetration: Preliminary results from skin penetration study conducted by FDA indicate that glycolic acid, at a relatively high level of acidity (pH 3), has a 20-30% rate of penetration. When less acidic (pH 7), the alpha hydroxy acid has a penetration of less than .5%. The pH 3-7 range reflects the spectrum of glycolic acid levels in consumer products. FDA reported the preliminary results of the study to the Cosmetic Ingredient Review Expert Panel in a May 12 letter ("The Rose Sheet" June 12, In Brief). FDA noted that the study is part of a larger study of skin penetration/metabolism for a homologous series of AHA." FDA plans to publish the results once the studies are completed...