Enhancement of transdermal iontophoretic delivery of a liposomal formulation of colchicine by electroporation

Iontophoresis of colchicine solution through electroporated skin showed maximum enhancement as compared to iontophoresis and electroporation alone. Encapsulation of colchicine in positively charged liposomes further augmented the delivery, with the amount of drug in the receptor after 24 h being 1348 +/- 342 mu g/cm(2) when iontophoresis was performed through electroporated skin as compared to 666 +/- 38 mu g/cm(2) when it was performed through non-electroporated skin and 41 +/- 18 mu g/cm(2) when only electroporation was performed. The impedance of the skin was observed to drop sharply due to electroporation, with a postpulse recovery of about 30% over 24 h. Also the total amount transported was compared to the total charge delivered in the case of each of the protocols. Hence this serves as initial evidence for potential of charged liposomes for the enhanced transdermal delivery of nonionized or neutral drugs using a combination of electroporation and iontophoresis.