Keratin Film Made of Human Hair as a Nail Plate Model for Studying Drug Permeation

The study developed a nail plate model using human hair keratin to address the limited availability of human nail plates for drug permeation studies. The keratin film was created through a process involving keratin extraction, dialysis, molding, solvent evaporation, and curing, resulting in a water-resistant film. The permeability of this film was tested with three markers representing different solubility properties and compared to bovine hoof. The keratin films, with a thickness of 120 μm, were found to be more permeable to rhodamine B than hooves, showing a 1.8-fold increase (p < 0.01). Further tests with penetration enhancers (urea, thioglycolic acid, and papain) indicated that keratin films were generally more susceptible than hooves. The study concluded that keratin films could potentially serve as a substitute for human nail plates, though the effects of penetration enhancers need careful consideration.