三氮唑核苷的热稳定性及其热分解动力学研究

THERMAL DECOMPOSITION KINETICS OF RIBAVIRIN AND ITS STABILITY

目的 研究三氮唑核苷的热稳定性及热降解 ,建立热解动力学方程。方法 采用TGS 2热重仪测定药物的热解曲线 ,用Achar微分法和Coats Redfern积分法确定热分解函数。结果 根据TG热解曲线求出三氮唑核苷的热解动力学参数及动力学补偿参数 ,用外推法求算出升温速率 β为 0℃·min-1时的活化能为 188 0 4kJ·mol-1。三氮唑核苷的热解动力学方程为dα/dt=Ae-EaRT( 1-α) 2 ;动力学补偿效应数学表达式为lnA =0 2 2 64Ea - 5 4 4 5 8。结论三氮唑核苷的热解活化能较高 ,热稳定性好。其胶囊制剂的热分解活化能略低于原药 。

AIM To study Thermal stabilities and thermal decomposition process of ribavirin and establish thermal decomposition kinetics equation. METHODS Thermal weight loss curve was obtained by thermogravimetry balance. Thermal decomposition function mode was also determined by Achar differential method and Coats Redfern integral method. RESULTS Thermal decomposition kinetics parameters and kinetics compensation parameters were calculated from thermogravimetry differential thermogravimetry data. Activation energy deduced by extrapolation under heating rate of 0℃·min -1 was 188 04 kJ·mol -1 . Thermal decomposition kinetics function expression was dα/dt=Ae -EaRT (1-α) 2 and the mathematic expression of the kinetic compensation effect is found to be ln=0 2264Ea-5 4458. CONCLUSION Ribavirin has high thermal stability because of its high thermal decomposition activation energy. The thermal decomposition activation of capsule is little lower than that of material,which indicates no evident difference in thermal stability for capsules and material.