Destabilization of Whole Skin Lipid Bio-liposomes Induced by Skin Penetration Enhancers and FT-IR/ATR (Fourier Transform Infrared/Attenuated Total Reflection) Analysis of Stratum Corneum Lipids

Abstract

Whole skin lipid bio-liposomes (skin bio-liposomes), in size ranging from 2 to 8μm, were prepared by a reverse phase evaporation technique using rat full thickness skin. Leakage of an encapsulated fluorescence probe, ANTS (δ-amino-1, 3, 6-naphtalenetrisulfonate), was measured by adding transdermal penetration enhancers (penetrants) into the medium where the skin bio-liposomes were present. Oleylamine induced a fast release of ANTS from the liposomes compared to laurylamine which showed a weak action. With these penetrants, the degree of ANTS release from the prepared bio-liposomes was found to correlate well with the results of frequency changes in the CH-asymmetric stretching band near 2920cm^-1 in the rat stratum corneum. The penetrant which caused relatively strong leakage of ANTS induced the significantly large shift of the peak toward the higher wavenumbers due to the perturbation in the structure of lipids of the stratum corneum. The skin bio-liposomes prepared from the rat full thickness skin could be useful in evaluating the penetrants.