Design and evaluation of sustained release matrix tablet of flurbiprofen by using hydrophilic polymer and natural gum

In the current study, an effort was made to formulate the sustained-release flurbiprofen matrix tablets by using HPMC (K100M) & natural gum like Xanthan gum as rate controlling polymer and to evaluate drug release parameters as per various release kinetic models. The tablets were prepared by direct compression method and various physical parameters were tested including hardness, friability, weight variation, thickness, and diameter. Dissolution study showed sustained-release profile for formulations F1 and F2, containing 15% and 25% HPMC (K100M) respectively. In contrast, F3 and F4 containing Xanthan gum showed rapid drug release profile and failed to sustain the release of drug within time interval. The drug release mechanism study predicted that the release of drug in F1 was mainly by diffusion meanwhile in F2 through erosion. The Korsmeyer-Peppas equation further confirmed that erosion mechanism involved in drug release for F2. Meanwhile, F1 exhibits anomalous release behaviour coupled with diffusion and erosion, in which diffusion still dominant. Statistical results showed that there was significant difference among formulations (p<0.05). Study revealed that by increasing concentration of polymer, the percentage of drug released reduced. F1 is selected as the best formulation to design sustained release flurbiprofen matrix tablet as it released 99% of drug after 12 hours and it applied the mix of diffusion and erosion in drug release mechanism, which is most optimum mechanism in sustained release formulation.