Improvement of transdermal permeation of captopril by iontophoresis

AIM: The feasibility of iontophoresis on the transdermal delivery of captop ril was studied. METHODS: Iontophoresis was employed for enhancing transder mal transport of captopril through rat skin in vitro and in vivo. RESULTS: It was demonstrated that the iontophoresis-induced flux of captopril was af fected by various factors such as pH, ionic concentration, and the concentr ation of captopril in donor compartments as well as the applied electric cu rrent intensity. Electric current could induce several-fold increase in cap topril flux with hydrogel. Skin permeation study in vivo in rats demonstrat ed that iontophoresis could effectively promote the transdermal transport o f captopril without significant skin irritation. Captopril concentration in plasma reached plateau ( similar to 0.9 mu g/mL) at 1 h after current appl ication and was maintained at the same level during the experiment. On the contrary, captopril could not be detected in plasma when the current was no t applied. No obvious skin irritation was observed after 9-h continuous ion tophoresis. CONCLUSION: Transdermal delivery of captopril can be effectivel y improved by iontopophoresis.