Passive and iontophoretic permeation of glipizide

In vitro iontophoretic delivery of glipizide across the pigskin was investigated. The experiment was carried out at three different donor drug concentrations using cathodal iontophoresis (current density 0.5 mA cm−2) with corresponding passive controls. At all concentration levels, iontophoresis showed enhanced permeation rate compared to passive controls (P < 0.01). For passive permeation, the steady-state flux significantly increased with the increase in donor drug concentration (P < 0.01). Passive process followed zero-order profile while the profile was nonlinear in iontophoresis. Competition by chloride ions released in the cathode compartment could be the reason. Flux enhancement was highest at the lowest drug load and lowest at the highest drug load. The target flux of glipizide was calculated to be 0. 4147 μmol h−1. As the highest flux obtained was 0.2727 μmol cm−2 h−1, it can be said that glipizide is a promising candidate for iontophoretic delivery.