Iontophoretic delivery of an insulin-mimetic peroxovanadium compound

The element vanadium has been shown to have insulin mimetic properties which gives it potential for use in the management of diabetes. Oral administration of vanadium has resulted in toxic side effects. Recently, a series of more potent vanadium compounds (peroxovanadium) have been synthesized which should be less toxic. However, there is no evidence that these compounds are orally active. Therefore, the feasibility of transporting peroxovanadium by iontophoretically enhanced transdermal delivery has been studied using several different donor conditions. The molecule was successfully delivered cathodally. Flux was linearly related to donor concentration and current density. The use of CaCl2 instead of NaCl as the donor salt significantly increased drug penetration. Transport increased with decreasing buffer concentration. Hairless mouse skin is a reasonable model for peroxovanadium flux across human skin, since penetration across the two membranes was within a factor of two. This work demonstrates that transdermal delivery of peroxovanadium compounds is feasible and that in vivo studies to test its efficacy in regulating blood glucose levels are warranted. (C) 1997 Elsevier Science B.V.