固态青霉素钾的降解动力学研究

Kinetic Study on the Degradation of Penicillin Potassium at Different Temperature and Relative Humidity

目的研究不同温度和相对湿度条件下青霉素钾降解的动力学规律。方法在恒温恒湿条件下使青霉素钾降解,定时测定其含量,并对获得的数据进行数学分析。结果青霉素钾的降解反应速率为-dc/dt=k(c0-c+B),降解曲线符合c=c0-Bexp(kt)+B,速率常数k可表达为k=Aexp(-Ea/RT)exp(mHr),其中活化能Ea=77.26kJ/mol,常数m=0.1159。结论反应速率表达式表述了青霉素钾的降解过程,符合其实际降解规律。

Objective To perform a kinetic analysis and formulation of the degradation of penicillin potassium in the solid phase at different temperature and relative humidity. Methods Penicillin potassium was incubated in a temperature-and-humidity-controlled oven at different temperature and relative humidity, and was determined by HPLC at suitable time intervals during the incubation. Results The reaction rate was expressed as -dc/dt =k （c0-c＋B）, where c is the residual concentration, k degradation rate constant, co original concentration and B a constant related to original concentration of degradant. Degradation curves were fitted with c=c0-Bexp （kt）＋B. The k was expressed as k=Aexp（-Ea/RT）exp（mHr）, where active energy Ea is 77. 26 kJ/mol and constant m 0. 1159. Conclusion The degradation of penicillin potassium could be expressed with c=c0-Bexp [Aexp （ -Ea/ RT ）exp （mHr ）t]＋ B.