Formulation and evaluation of natural gum-based sustained release matrix tablets of flurbiprofen using response surface methodology

Background: This research work was done to design oral sustained release matrix tablets of water-insoluble drug, flurbiprofen, using natural gums as the matrix polymers and to evaluate the drug release characteristics using response surface methodology. The central composite design for two factors at five levels each was employed to systematically optimize drug release profile. Method: Matrix tablets were prepared by direct compression technique. Xanthan and acacia gums were taken as the independent variables. Fourier transform infrared spectroscopy studies were also performed to find out the stability of drug during the direct compression and to check the interactions between polymers and drug. Percent drug release in 2 hours and percent drug release in 8 hours were taken as response variables (Y1 and Y2, respectively). Results: Both the polymers were found to have significant effect on the drug release. Polynomial mathematical models, generated for the response variables using multiple linear regression analysis, were found to be statistically significant (P < 0.05). Contour plots were drawn to depict the relationship between response variables and independent variables. Conclusion: The formulated matrix tablets followed zero-order kinetics with negligible drug release in 0.1 N HCl at pH 1.2, which was the objective of this study to produce a formulation avoiding the gastric effects of flurbiprofen.