Fabrication and evaluation of Eudragit polymeric films for transdermal delivery of piroxicam.

The aims of this work were to develop and characterize the prolonged release piroxicam transdermal patch as a prototype to substitute oral formulations, to reduce side effects and improve patient compliance. The patches were composed of film formers (Eudragit) as a matrix backbone, with PVC as a backing membrane and PEG200 used as a plasticizer. Results from X-ray diffraction patterns and Fourier transform-infrared spectroscopy indicated that loading piroxicam into films changed the drug crystallinity from needle to an amorphous or dissolved form. Piroxicam films were prepared using Eudragit RL100 and Eudragit RS100 as film formers at various ratios from 1:0 to 1:3. Films prepared solely by Eudragit RL100 showed the toughest and softest film, while other formulations containing Eudragit RS100 were hard and brittle. Drug release kinetic data from the films fitted with the Higuchi model, and the piroxicam release mechanism was diffusion controlled. Among all formulation tested, Eudragit RL100 films showed the highest drug release rate and the highest drug permeation flux across human epidermal membrane. Increasing drug loading led to an increase in drug release rate. Eudragit can be used as a film former for the fabrication of piroxicam films.