Gelatin-stabilised microemulsion-based organogels: rheology and application in iontophoretic transdermal drug delivery

Gelatin-containing microemulsion-based organogels (MBGs) have been formulat ed using pharmaceutically acceptable surfactants and oils such as Tween 85 and isopropyl myristate. MBG formulations were subject to rheological study and their utility in transdermal drug delivery examined. Unlike most organ ogels, MBGs are electrically conducting and have been successfully employed in this study for the iontophoretic delivery of a model drug through excis ed pig skin. Iontophoresis using MBGs gave substantially higher release rat es for sodium salicylate compared to passive diffusion, and fluxes were pro portional to the drug loading and the current density. MBGs provide a conve nient means of immobilising the drug and are theologically similar to their hydrogel counterparts at comparable gelatin concentrations. MBGs also appe ar to offer improved microbial resistance in comparison to aqueous solution or hydrogels. (C) 1999 Elsevier Science B.V. All rights reserved.