Application of the transformed Potts-Guy equation to in vivo human skin data

Data developed by Wenkers and Lippold for the flux of 10 nonsteroidal anti-inflammatory drugs from light mineral oil (MO) through human skin in vivo has been analyzed using the transformed Potts-Guy equation. The analysis shows that the flux is dependent not only on the solubility in MO (S(MO)), but also on the solubility in acidic water (S(AQ)). This dependence of flux on S(AQ) shows that the previously reported dependence of flux on S(AQ) from in vitro experiments using hairless mouse skin is not an artifact of the in vitro experiments but is due to a characteristic of the skin barrier. Further inspection of the equations used by Wenkers and Lippold in their analyses of their data shows that the equations are variations of the transformed Potts-Guy equation.