[Formulation Optimization of Zuojin Floating-Bioadhesive Pellets by Central Composite Design-Response Surface Methodology].

Objective: To optimize the formulation of Zuojin floating-bioadhesive pellets by the central composite design-response surface methodology (CCD-RSM).

Methods: In the formulation design using CCD-RSM, independent variables were the amounts of sodium bicarbonate (X1), HPMC (X2) and MCC (X3) as factors. Small pills roundness, 12 h floating rate and the percentages of in vitro cumulative releases at 2,6 and 12 h were dependent variables. Multilinear and quadratic model were used to estimate the relationship between the dependent and the independent variables. According to best model, the contour plots and RSM were drawn, and the optional formulation was selected. According to the optional formulation,the pellets were prepared and validated.

Results: The quadratic was the best fitting mode. Small pills roundness was 15.04 °. 12 h floating rate was 75.07%. Percentages of in vitro cumulation release at 2,6 and 12 h of the option formulation pellets was 27.01%, 70.00% and 84.61%, respectively. The actual value was close to the predicted value. Deviation was less than 5%.

Conclusion: Quadratic model was preferred in the optimization of formulation due to the statistical confidence. The multi-objective simultaneous optimization of Zuojin floating pellet formulation can be achieved by the central composite design-response surface methodology.