Use of electroporation to accelerate the skin permeability enhancing action of oleic acid

Rat skin permeability after treatment by electroporation (new ly developed frog type electrode, 100V, 10 pulses), oleic acid/propylene glycol (PG) and a combination of both were investigated using Fourier transformed infrared attenuated total reflectance (FT-IR/ATR) analysis. Electroporation immedia tely disordered the stratum corneum lipid structure up to a certain thresho ld level. This action lasted throughout the experiment. This may be attribu ted to the formation of long lifetime of metastable lipid structures, which may allow molecules to pass to the inside of the stratum corneum due to th e electroporation-induced fluidized lipid membranes, Electroporation also a ltered the protein structure of the stratum corneum, When electroporation w as combined with 0.05 M oleic acid/PG, uptake of oleic acid and PG into the stratum corneum was remarkably accelerated compared to the application of only 0.05 ill oleic acid/PG to the skin. This indicates that electroporatio n enables oleic acid and PG to penetrate the stratum corneum easily by disr upting the structure of the latter pc transfer into the dermis from the epi dermis was accelerated, not because of the direct action of electroporation on the dermis, but because electroporation induced the rapidly disordering action of oleic acid on the stratum col neum. Lipid-soluble indomethacin p ermeated the skin more rapidly when the skin was treated with electroporati on plus oleic acid/PG than with 0.05 M oleic acid/PG in vitro.