Preparation and characterization of reverse micelle based organogels of piroxicam

The solubilization of piroxicam to increase transdermal permeation rate was attempted by incorporating the drug in reverse micelle systems consisting of lecithin/isopropyl myristate/water [RMS-1] and sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/water [RMS-2]. The change in polarity of water present in the water pool formed by reverse micelles resulted in a solubilization of piroxicam. These systems were used for the formation of reverse micellar organogels RMO-1 and RMO-2 by means of either varying hydration ratio (Wo) or by addition of a macromolecule, e.g. gelatin, into the system or by taking both the parameters in consideration. These systems were evaluated for physical properties, toxicology, in vitro and in vivo transdermal permeation. Significant (p < 0.01) inhibition of carrageenan induced rat paw oedema was observed for products RMO-1 and RMO-2 and a marketed transdermal product after 3 h.