线性降解程序变湿法研究青霉素钾的稳定性

Stability of penicillin potassium with linear degradation programmed humidifying experiments

报道了一种新的研究湿度对固体药物稳定性影响的试验方法——线性降解程序变湿法。按照这一变湿规律进行程序变湿药物稳定性试验能最大限度地使药物在高湿和低湿范围内降解程度一致,提高了试验的精密度。作者以青霉素钾为模型药物,采用线性降解程序变湿法和指数程序变温法进行试验,求得了Ea,m,A和t0.9等动力学参数。结果表明,新方法测定结果的精密度明显优于文献报道的程序变湿变温法。

A linear degradation humidifying model for drug stability experiment is introduced.This new humidifying model is presented as: H_r=-1Mln{exp(-MH_(r,0))-[exp(-MH_(r,0))-exp(-MH_(r,m))]tt_m}.Where H_r is the relative humidity;t is the time;H_(r,m) and t_m are the final relative humidity and time of the experiment,respectively.M is humidifying constant used in the humidifying program.In the new programmed humidifying model,a linear relationship between the content function of drugs and the relative humidity is obtained,the degradation of drugs can be more uniform within different humidity ranges and the experimental results are more accurate than those in the reported linear humidifying model.The stability of penicillin potassium,as a solid state model,was investigated by the linear degradation programmed humidifying and the exponential heating experiments. The results indicated that the kinetic parameters obtained by the linear degradation programmed humidifying and the exponential heating models were significantly more precise than those obtained by the linear programmed humidifying and the reciprocal heating models.