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.