Keratin immobilized on silica as a new stationary phase for chromatographic modelling of skin permeation.

Skin permeability of organic compounds depends on their lipophilicity but can also be affected by compounds interactions with specific skin components. A good chromatographic model of percutaneous penetration determined solely by lipophilicity is provided by the immobilized artificial membrane (IAM) columns. To complete the model a new high-performance liquid chromatographic (HPLC) stationary phase was prepared by physical immobilization of keratin on silica support. The keratin immobilized on silica has properties typical for the reversed-phase materials but it retains specifically acidic solutes. The keratin column can be used to conveniently compare keratolytic properties of xenobiotics. It was demonstrated that retention parameters determined on a keratin column can be combined with the retention parameters determined on the IAM column to predict differences in skin permeability within a class of drugs. It has been postulated that HPLC can model skin permeation thus reducing research time and costs as well as the use of laboratory animals.