Iontophoretic transdermal drug delivery system using a conducting polymeric membrane

This work investigated the application of a porous polyaniline (PANi) membrane as a conducting polymeric membrane as well as an electrode in an iontophoretic transdermal drug delivery (TDD) system. Model drugs studied were: caffeine (MW: 194.2), lidocaine HCl (MW: 270.8) and doxycycline HCl (MW: 480.1). The PANi membrane was first tested as a simple membrane between the donor and receptor solutions; it provided satisfactory permeation profiles; the observed flux values were well described by a simplified mass transport model. A mouse skin was then mounted beneath the PANi film; such a composite system also presented satisfactory permeation profiles. Iontophoretic TDD experiments were next performed using both Ag vertical bar AgCl electrodes and PANi vertical bar AgCl electrodes for comparison; a PANi anode replaced the Ag anode in the last set. For doxycycline HCl, the flux and the 24-h accumulation from the PANi vertical bar AgCl set were 94.4 +/- 81.2 mu g/cm(2) h and 2760 +/- 3980 mu g/cm(2), respectively; those from the Ag vertical bar AgCl set were zero. For lidocaine HCl, the flux and 10-h accumulation from the PANi vertical bar AgCl set were, respectively, 43 +/- 15 mu g/cm(2) h and 392 130 mu g/cm(2); the corresponding values from the Ag vertical bar AgCl set were 48 20 mu g/cm(2) h and 348 78 mu g/cm(2). Porous polyaniline membrane appears to be capable of replacing the Ag part of Ag vertical bar AgCl electrode system; further such a membrane can exercise additional control over agent transport rate. Aqueous-organic partitioning system through the porous membrane of PANi was tested with this novel technique as well. Because of the rather low porosity of the synthesized PANi film, such a system did not yield a high permeation rate. (c) 2008 Elsevier B.V. All rights reserved.