【摘要】 目的 :研究了药物的热稳定性 ,快速、科学、经济地预测药物的有效贮存期 .方法 :用 TG- DTG热重法测定药物的热降解曲线 ,用 Coats- Redfern积分法求算出热降解反应为一级反应时的动力学参数活化能 E和指前因子A,根据所得到的动力学参数求算出药物在贮存温度—室温 (2 5℃ )下降解反应速率常数 k,进一步探讨药物已知有效期与反应速率常数 k的负对数 pk的相关性 .结果 :市售药物有效期与热分析动力学方法求算得到的 (室温 2 5℃ )pk存在相关性 ,根据市售药物贮存期可将药物室温 (2 5℃ )下 pk划分为 3个区间 :药品的有效期在 1.5 a或 2 a,定为区间 ,pk<7.5 ;药品的有效期为 3a,定为区间 ,7.5 <pk<11;药品的有效期为 4 a或 5 a,定为区间 ,pk>10 .5 .结论 :根据室温 (2 5℃ )下降解反应速率常数 k和药物有效期的相关性 ,通过热分析动力学求算法可初步预测未知药物贮存期 .更多还原

【Abstract】 Aim:to study the thermal stabilities of drugs and to predict the shelf time of drugs quickly, scientifically, economically. Methods:thermogravimetry (TG) and differential thermogravimetry (DTG) technique were used to determine the thermal decomposition curves of drugs, and Coats Redfern integral method was used to calculate activation energy E and pre exponential factor A under 1th order reaction model. The decomposition velocity constant k at room temperature was calculated with obtained kinetics parameters. The correlation between decomposition velocity constant k and shelf times of some known drugs was further discussed. Results:there existed correlation between decomposition velocity constant k and shelf time. The values of p k , which were calculated, was divided into three sectors according to shelf times. When p k <7.5 insector Ⅰ, shelf time was 1.5 or 2 years; when 7.5<p k <11 in sector Ⅱ the shelf time was 3 years; and shelf time was 4 or 5 years when p k >10.5 in sector Ⅲ. Conclusion:according to the correlation between decomposition velocity constant k and shelf time of drugs, a simple method was suggested to predict shelf times of some unknown drugs by means of thermal analysis kinetics calculation.更多还原