羟丙基-β-环糊精对穿琥宁水溶液稳定性的影响

Influence of Hydroxypropyl-β-Cyclodextrin on Stability of Potassium Dehydroandrographolidi Succinas

目的研究羟丙基-β-环糊精（HP-β-CD）对穿琥宁稳定性的影响。方法分别考察穿琥宁溶液在不同的pH（7-9）值，不同的HP-β-CD（3.62～108．7mmol·L^-1）浓度，不同温度（60-90℃）下的降解动力学。使用曲线拟合的方法计算包合物的表现降解速率常数以及稳定常数。结果穿琥宁在不同浓度的HP-β-CD溶液中的降解符合一级动力学方程，表观降解速率常数（kohs）与HP-β-CO浓度不成直线关系，随HP-β-CO浓度增加而提高，最后趋于恒定．温度越低，HP-β-CD的稳定作用越明显。结论在该研究中HP-β-CD可以增加穿琥宁在溶液中的稳定性。

OBJECTIVE To investigate the effect of hydroxypropyl-β-cyclodextrin（HP-β-CD） on the stahility of potassium dehydroandro- grapholidi succinas（DAS-K） in aqueous solution.METHODS The degradation kinetics of DAS-K in aqueous solution were investigated at different pH, different HP-β-CD concentration and various temperatures. The rate constant（kc） for the degradation of DAS-K in inclusion complex and equilibrium constant（KA） were calculated by the curve-fitting method. RESULTS The hydrolytic degradation of DAS-K followed first-order kinetics in different HP-β-CD concentration. The apparent rate contant（kohs） for the hydrolysis of the drug was not a linear function of HP-β-CI） concentration and asymptotically approached a minimum value with increasing HP-β-CD concentration. The stabilizing effect of HP-βCD on DAS-K was more significant at low temperature. CONCLUSION HP-β-CD represents a visible mearns of stabilization of DAS-K solution in the study.