ABSTRACT
OBJECTIVE: To optimize the formulations of Zizyphi Spinosi Semen flavonoid dropping pills by central composite design-response surface methodology. METHODS: Central composite design-response surface methodology was applied to optimize the preparation process with the dropping distance, dropping temperature, and cooling temperature as independent variables, while dependent variables were the variance of weight, spherical degree, and dissolution time. SPSS software was used to fit multivariate linear equation and second-order polynomial equation for experimental data. Response surface and contour plot were delineated according to best-fit mathematic models by Origin software, and the optimum formulation was selected by response surface. RESULTS: Quadratic multinomial model was better than multivariate linear model, and the regression coefficient was 0.981. The bias between the observed and predicted values of the optimum process was negligible, indicating the high predictability of the model. CONCLUSION: The model established by central composite design-response surface methodology and SPSS software is accurate for prediction and can be used to optimize the preparation process of Zizyphi Spinosi Semen flavonoids dropping pills.