Permeability test for transdermal and local therapeutic patches using Skin PAMPA method.

Abstract Using the skin as absorption site presents unique advantages that have facilitated the progression of transdermal drug delivery in the past decades. Efforts in drug research have been devoted to find a quick and reproducible model for predicting the skin permeation of molecules. The Parallel Artificial Membrane Permeability Assay (PAMPA) has been extended for prediction of transdermal permeation by developing a model with completely artificial membrane, which can mimic the permeation through the stratum corneum. The present study aims to extend the Skin PAMPA method for testing transdermal and local therapeutic patches. The original method was modified and seven commercially available transdermal and local therapeutic patches with four different active pharmaceutical ingredients (nicotine, fentanyl, rivastigmine and ketoprofen) were studied. Data were compared to the declared delivery rates that are indicated by the manufacturers. Ex vivo permeation study was also performed in order to compare the permeated amount of the released drugs obtained by the two methods. The flux across the artificial membrane as well as the human skin ( ex vivo ) has been calculated and compared to the in vivo flux deduced from the labelled delivery rate and the active area of the patches. The results suggest that Skin PAMPA system can serve as a useful tool for evaluation and classification of the transdermal patches.