Effect of current density on the iontophoretic permeability of benzyl alcohol and surface characteristics of human epidermis

Abstract

Benzyl alcohol (BA), a non-electrolyte, was selected as a probe permeant to investigate its iontophoretic transport through human epidermis. The flux of BA and [3H]water were greater during anodal than cathodal iontophoresis. Increases in current density enhanced the permeability coefficient of BA during iontophoresis. The greater permeability of BA during anodal iontophoresis than cathodal may be due to permselective nature of human epidermis at physiological pH 7.4 for positively charged buffer ions and hence, associated [3H]water and BA. Thus, it is possible to enhance and control the transdermal transport of non-electrolyte by iontophoresis. Scanning electron microscopy of the human epidermis treated with iontophoresis showed greater loosening of epidermal cells and distention in intercellular space with increasing current densities.