Partial ablation of porcine stratum corneum by argon-fluoride excimer laser to enhance transdermal drug permeability

To enhance skin permeability to medicine, the argon - fluoride excimer laser (ArF laser) was used to partially ablate the stratum corneum. Skin permeability to dextran ( 20 kDa) was studied in the Yucatan micropig skin in vitro. The cumulative amount of dextran permeating across the full-thickness skin was not detected for 30 h in the unirradiated skin; we obtained up to 90.5 mu g/cm(2) in laser-irradiated skin. In the case where the total laser energy was kept constant at 7.1 J/cm(2), permeability was mainly influenced by laser fluence rather than laser pulses. Many granular structures of about 2 mu m were found on the stratum corneum surface of ablated skin. Size and density of these structures were changed according to irradiation conditions. Skin permeability may be estimated by these structural changes. Our partial stratum corneum ablation by ArF laser could be suitable for transdermal drug delivery.