星点设计-效应面法优化琥珀酸美托洛尔缓释微丸处方

Formulation optimization of metoprolol succinate sustained release pellets using central composite design-response surface methodology

目的：通过星点设计-效应面法优化琥珀酸美托洛尔（ MS）缓释微丸处方工艺。方法采用蔗糖丸芯，以乙基纤维素为包衣材料，模型药物MS为致孔剂，通过流化床底喷工艺制备MS缓释微丸。以致孔剂比例和包衣增重为考察因素（自变量），微丸1，4，8，12，16 h的释放度为考察指标（因变量），采用两因素五水平星点设计对处方进行优化。根据自变量和因变量数据，进行数学方程拟合并描绘效应面，选择最佳处方工艺进行验证实验。结果与结论数学方程拟合结果表明二项式方程拟合度较高。根据效应面优化的最佳自变量范围可知，致孔剂比例为16％～18％，包衣增重为20％～25％。优化的缓释微丸药物释放度1 h达到9．15％，消除了释放初期的迟滞相，且能够在较长时间内维持良好的缓释作用。通过星点设计-效应面法优化的MS缓释微丸处方工艺稳定可行。

Objective To optimize the formulation of metoprolol succinate （ MS） controlled release pellets by central composite design-response surface methodology .Methods MS sustained-release pellets were prepared using sugar pellet cores as starter beads , ethyl cellulose as coating materials and MS itself as a pore former .The formulation of MS sustained-release pellets was optimized by a central composite design with two factors at five levels .These two factors （ two independ-ent variables） were the pore former level and coating level , and the evaluated indexes （ namely dependent variables ） included the in vitro cumulative release percentages of MS at 1, 4, 8, 12 and 16 h, respectively.Results and Conclusion The results of mathematical equation fitting suggested that the second-order quadratic model was the optimal fitting equa-tion.According to the response surfaces , the optimum values at the pore former level and coating level weve ranged from 16%to 18%and 20% to 25%, respectively .The in vitro cumulative release percentage of MS from the pellets at 1 h reached 9.15%,which consequently eliminated the lag phase in the initial release period and exhibited a good sustained-release effect.Central composite design-response surface methodology can be applied to optimizing the coating formulation for MS sustained release pellets .