光和温度对盐酸普鲁卡因注射液稳定性的影响

目的研究盐酸普鲁卡因注射液在光和热同时作用下的稳定性。方法采用在高温下进行光照的实验方法。结果该药物在恒温加速实验或高温光照实验中的降解均服从一级反应动力学规律。在光和热同时作用下的总的降解速率常数k_total由两部分构成：k_total=k_dark+k_light，k_dark和k_light分别为热反应降解速率常数和光反应的降解速率常数，且k_light=A_light·E·exp(-E_a,light/RT)。式中E为光源的照度，A_light是与光源种类有关的实验常数,E_a,light亦为一实验常数。结论由于k_light的表达式与Arrhenius方程形式类似,式中E_a,light可能为光化反应次级过程的表观活化能,其值与光源种类无关支持了这一观点。

Influence of light and temperature on the stability of procaine hydrochloride injection

AIM: To study the influence of light and heat on the stability of procaine hydrochloride injection. METHODS: Accelerated tests upon exposure to light at high temperatures were employed. RESULTS: In experiments with either isothermal heating or exposure to light at high temperatures, the drug degradation rate obeys first-order kinetics. The total rate constant, ktotal, caused by both light and heat can be divided into two parts: ktotal = kdark + klight, where kdark and klight are the rate constants caused by heat and light, respectively. The klight can be expressed as klight = Alight x E x exp(-Ea,light/RT). Where E is the illuminance of light, Alight is an experimental constant related to light sources, and Ea,light is an experimental constant. CONCLUSION: Because the form of klight is similar to the Arrhenius equation, it is suggested that Ea,light might be the observed activation energy of the rate-determining step of the subsequent processes of the photochemical reaction. This viewpoint is supported by the fact that the Ea,light is independent of light sources.