EFFECT OF CURRENT-DENSITY ON THE IONTOPHORETIC PERMEABILITY OF BENZYLALCOHOL AND SURFACE CHARACTERISTICS OF HUMAN EPIDERMIS

Benzyl alcohol (BA), a non-electrolyte, was selected as a probe permea nt to investigate its iontophoretic transport through human epidermis. The flux of BA and [H-3]water were greater during anodal than cathoda l iontophoresis. Increases in current density enhanced the permeabilit y coefficient of BA during iontophoresis. The greater permeability of BA during anodal iontophoresis than cathodal may be due to permselecti ve nature of human epidermis at physiological pH 7.4 for positively ch arged buffer ions and hence, associated [H-3]water and BA. Thus, it is possible to enhance and control the transdermal transport of non-elec trolyte by iontophoresis. Scanning electron microscopy of the human ep idermis treated with iontophoresis showed greater loosening of epiderm al cells and distention in intercellular space with increasing current densities. (C) 1998 Elsevier Science B.V. All rights reserved.