Abstract
The ablation of stratum corneum (SC) by the pulsed-laser irradiation is one of the method to enhance the drug penetration in transdermal drug delivery system (TDDS). In this study, we have tried to enhance the drug penetration without the ablation of SC using 6μm-FELs. Lidocaine was used as the drug on this study. The enhancement of lidocaine penetration was measured by HPLC (High Performance Liquid chromatography). As results, the skin samples irradiated with FEL had the SC on the skin surface, the thermal relaxation times of the skin samples on 6-μm region were shorter than the macropulsese of FEL, 15μsec, because the skin samples were given the efficient thermal effect by the laser irradiation. It read to the enhancement of TDDS. The Lidocaine flux (mg/cm2/h) at 0.5 hour with the irradiated skin using an FEL was enhanced 10 fold faster than with the non-irradiated skin. We have demonstrated the effectiveness of an MIR-FEL (6-μm wavelength) irradiation in the TDDS. In conclusion, the skin samples were enhanced without the SC removal by the laser irradiation of the absorption peak of amide region in the skin sample.
