Formulation and in vitro evaluation of transdermal matrix patches of Diclofenac sodium (original) (raw)

In this work an attempt was made to formulate and evaluate transdermal matrix patches for controlled delivery of diclofenac sodium. Low molecular weight, shorter half-life and low oral bioavailability due to first pass metabolism of diclofenac sodium made it a suitable drug candidate for the development of transdermal patches. Matrix-type transdermal patches containing diclofenac sodium were prepared using different ratios of ethylcellulose (EC) and polyvinylpyrrolidone K-30 (PVP K-30) by solvent evaporation technique. All the patches were evaluated for the permeation along with physicochemical studies including thickness, weight variation, moisture content, moisture uptake, flatness, folding endurance and drug content. The results of physical parameters ensured integrity and applicability of the patches. The in vitro drug permeation was best fitted with the zero order kinetics. Also the diffusion coefficient of release profiles (slope) had a value of > 1, which indicated super case II transport. Based on the above observations, it can be reasonably concluded that the release pattern of diclofenac sodium can be controlled by maintaining appropriate proportion of EC and PVP-K30 in the matrix patch.