Optimization of Tinidazole Colon-Targeted Bioadhesive Tablets Formulation by Central Composite Design-Response Surface Methodology

OBJECTIVE To optimize the formulation of tinidazole colon-targeted bioadhesive tablets by the central composite design-response surface methodology (RSM plus CCD). METHODS In the formulation design using RSM plus CCD ,independent variables were the amounts of Alginic Acid and HPMC,and weight gain. The percentages of in vitro cumulative releases at 3 and 12 h were dependent variables. Multilinear and quadratic models were used to estimate the relationship between the dependent and the independent variables,and to delineate RSM and overlay contour plots in order to select the optimal formulations with the application of hypothesized in vitro cumulative releases (%) at 2 and 24 h. RESULTS The quantitative relationships between three factors and two evaluation indexes were characterized. In vitro release test of one selected optimal formulation indicated that were high approximation between the observed and estimated values. Moreover,quadratic model showed better prediction capability than multilinear model. CONCLUSION Quadratic model was preferred in the optimization of formulation due to the statistical confidence. The multi-objective simultaneous optimization of tinidazole colon-targeted bioadhesive tablets formulation could be achieved by the central composite design and response surface methodology.