Gel Based lontophoretic Delivery System for Enhanced Transdermal Permeation of Alendronate Sodium

The purpose of the present study was to explore the passive and electrically assisted transdermal transport of Alendronate Sodium (AS) by iontophoresis in combination with penetration enhacers. For better bioavailability, better patient compliance, and prevention of gastro-intestinal irritation of AS, an iontophoretic drug delivery system of AS gel was formulated using Carbopol-940. Optimization of gel indicated the suitability of the Carbopol gel for transdermal iontophoretic delivery of AS. The study was conducted using silver–silver chloride electrodes across hairless Guinea pig skin. The effects of Current density, Pulse current and Penetration enhancer on the AS permeation were investigated. Iontophoretic transport of AS was found to increase with an increase in the current density. In case of pulsatile iontophoresis permeation of AS was observed to be higher at ON: OFF ratio of 1:1 in comparison to ON:OFF ratio 1:2, 1:4. Cathodal pulsed iontophoresis with penetration enhancer i.e Dimethyl sulphoxide (DMSO) significantly increased the AS skin permeation as compared with the passive controls.