Electroporation and ultradeformable liposomes; human skin barrier repair by phospholipid.

This work investigated the effect of electroporation on human epidermal penetration of a model neutral lipophilic compound (estradiol) from saturated aqueous solution and when encapsulated in ultradeformable liposomes. Total amount penetrated and skin deposition were compared with values obtained from passive diffusion. The effect of electrical pulsing on liposome size was investigated. The action of phosphatidylcholine on skin that was structurally altered by such pulses was determined. Electroporation did not affect liposome size. Skin pulsing considerably increased estradiol penetration and skin deposition from solution, relative to passive delivery, with subsequent partial recovery of skin resistance to molecular penetration. Surprisingly, with liposomes, electroporation did not markedly affect estradiol skin penetration. Importantly, liposomal phosphatidylcholine applied during or after pulsing accelerated skin barrier repair, i.e. provided an anti-enhancer or retardant effect.