嘌呤药物的热解过程及其热分解动力学

目的研究嘌呤类药物的热解过程及非等温动力学。方法用红外光谱技术、加速稳定性试验方法和热重仪分析方法测定分解过程,用Ozawa法以及Coast-Redfern法和MKN法处理数据确定热分解函数。结果确定了阿昔洛韦(aciclovir,Acv)、喷昔洛韦(penciclovir,Pcv)热解过程和中间产物,得到热解动力学参数活化能Ea、指前因子A。结论加速稳定性试验与热重法的计算结果一致,喷昔洛韦的热稳定性大于阿昔洛韦;两者热解第一步具有相同的中间产物鸟嘌呤,且动力学方程相同:dα/dt=Ae^-Ea/RT2(1-α)^3/2,均为1.5级反应过程。

STUDIES ON THE THERMAL DECOMPOSITION PROCESS AND KINETICS OF PURINE DRUGS

AIM: To study the thermal stability, decomposition process and kinetics of such purine pharmaceuticals as aciclovir (Acv), penciclovir (Pcv), and their parent substance, guanine. METHODS: Using infrared technique, accelerating test method and thermogravimetry to investigate the thermal decomposition processes and using Coast-Redfern method, MKN method and Ozawa method to deal with the data to get kinetic functions. RESULTS: The decomposition process and the formed products were derived, the kinetic model function was suggested by comparison of the kinetic parameters. CONCLUSION: Pcv and Acv's degrading product for the first step is guanine. The sequences of their thermal stabilities is: Pcv > Acv. The two drugs' kinetic equation of thermal decomposition is expressed as: da/dt = Ae-Ea/RT2(1-alpha)3/2.