Improvement of peripheral microcirculation by iontophoretic application of beraprost sodium

The pharmacological effects of iontophoretically applied beraprost sodium on peripheral microcirculation were investigated. Beraprost sodium in normal saline (10 μg/mL) remained stable after iontophoretic application of 6V for 3h. In an in vitro study, iontophoretically administered beraprost sodium (10, 100 and 500 μg/mL) was transported across hairless mouse skin in a time-dependent manner with the amount of permeated drug increasing in a dosedependent manner; however, the drug did not permeate the skin by passive transport. In a clinical study, 12 patients with arteriosclerosis obliterans were given beraprost sodium (20 μg) iontophoretically on the dorsum of the foot. As a control, normal saline was applied iontophoretically on a separate day. The rate of increase in cutaneous blood flow was measured by laser Doppler flux (LDF). The percentage increase in LDF was significantly higher in the beraprost sodium group than in the control group (224.7 ± 132.9% vs. 134.6 ± 57.0%, p<0.01). No change in LDF was observed in untreated legs. These results indicated that iontophoretically applied beraprost sodium was effective in improving the impaired microcirculation resulting from peripheral arterial occlusive disease while reducing the systemic effects and enhancing local benefits. This drug delivery system may be useful in managing severely ischemic legs.