Abstract: AimTo investigate the effect of iontophoresis on skin permeation of defibrase. Methods Iontophoresis was carried out in side-by-side chambers, excised rat skin membrane (RSM) or human epidermis membrane (HEM). The effects of electrode polarity, permeation medium pH and ionic strength were evaluated. ResultsPermeation of defibrase caused by anodal iontophoresis was more effective ［the apparent permeability coefficient was (1.2±0.4)×10^-4 cm·h^-1］ than that of cathodal iontophoresis［(4.3±1.4)×10^-5 cm·h^-1］. The amount of permeated defibrase caused by anodal iontophoresis in pH 7.4 medium was (25±5)×10^-14 mol·cm^-2, which was higher than that of in pH 6.4 permeation medium ［(15±4)×10^-14 mol·cm^-2］. Conclusion Iontophoresis could enhance skin permeation of defibrase. Electroosmotic flow effect played an important role.