Iontophoresis: electrorepulsion and electroosmosis.

Over the last 10-15 years, the electrical enhancement of drug delivery across the skin has undergone intense investigation. During this period, considerable amounts of experimental data have been generated, and the successful enhancement of a diverse array of molecules has been achieved. Indeed, the commercial exploitation of the method can be envisaged within the next few years. Despite this progress, however, the mechanistic understanding of iontophoresis remains a challenging scientific question that is yet to be fully resolved. The routes of permeation under the influence of an applied electrical potential, and the molecular interactions of the transporting drug with these pathways, hav…