Diffusion studies of diclofenac sodium topical gel using different synthetic membranes

Diffusion of the drug from a formulation and across membranes simulating biological cell membranes is the major concern to be taken under consideration while formulating any dosage form. This brings on a major role in those which are to be applied along the skin, since drug needs to first release from the polymer matrix then enter systemic circulation via the skin. The purpose of the study was to compare the dispersion rate of diclofenac sodium from the gel formulation across five different synthetic membranes. In this work, we worked to measure the drug release profile using and using various kinetic models, found out the mechanism of diffusion through membranes on the drug release profile. The evaluation was done by an in vitro drug release system in the laboratory using Franz diffusion cell. Diclofenac sodium topical gel was formulated using carbopol 934 as the gel-forming agent(1). Diffusion studies showed that the highest release was given by mixed cellulose ester membrane (83.16%) in 71.5 hrs. Followed by cellulose acetate membrane (78.1%), cellulose acetate nitrate membrane (75.6), polyether sulphone membrane (70.8%) and sigma cellulose membrane (56.39%). Drug release followed first-order kinetics and Higuchi's model of diffusion from all the membranes with case II and super case II transport mechanisms.