IONTOPHORETIC TRANSPORT THROUGH POROUS MEMBRANES USING SCANNING ELECTROCHEMICAL MICROSCOPY - APPLICATION TO INVITRO STUDIES OF ION FLUXES THROUGH SKIN

Scanning electrochemical microscopy (SECM) is used to map localized io ntophoretic fluxes of electroactive species through porous membranes. A method is described that allows both the rate of transport of specie s from a microscopic pore and the pore's diameter to be measured. SECM images and analyses of synthetic porous membranes (track-etched polyc arbonate and mica membranes) and hairless mouse skin are reported. Pre liminary analysis of SECM images of the mouse skin indicates that a si gnificant percentage of the iontophoretic flux occurs through pores as sociated with hair follicles.