乙酰基β-环糊精对阿莫西林化学稳定性影响的动力学研究

Kinetics study on the effect of triacetyl-β-cyclodextrin to chemical stability of amoxicillin

目的考察乙酰基β-环糊精对阿莫西林化学稳定性的影响。方法采用恒温加速法考察阿莫西林在乙酰基β-环糊精不同浓度,不同温度下的水解动力学;通过数学拟合,确定水解动力学方程;运用Arrhenius公式预测阿莫西林水解反应的活化能及有效期(t0.9)。结果阿莫西林的水解反应符合一级动力学模型。随着乙酰基β-环糊精用量的增加有效期变长;当乙酰基β-环糊精与阿莫西林的摩尔比达到2:1时,水解反应速率最小,活化能达到最大。结论乙酰基β-环糊精的存在能显著减小阿莫西林的水解速率,提高其化学稳定性。

Objective To investigate the effect of triacetyl-β-cyclodextrin(TA-β-CD) on chemical stability of amoxicillin(AMX). Method The constant temperature acceleration test was used to research hydrolysis kinetic of amoxicillin at different TA-β-CD contents and at different temperatures. The kinetic equation of hydrolysis reaction was confirmed by mathematics fitting. The activity energy and t0.9 of AMX hydrolysis reaction was predicted by Arrhenius equation.Results The result shows that hydrolysis reaction of amoxicillin is consonant with first-order reaction kinetics and the linear regressive equation can be determined. With the content of TA-β-CD increasing, the t0.9 of AMX increases. When the molar ratio of TA-β-CD and AMX is 2:1, the rate of hydrolysis reaction reaches minimum, the activity energy of hydrolysis reaction reaches its maximum. Conclusion The chemical stability of AMX increases and its hydrolysis rate decreases with the existence of TA-β-CD.