盐酸普鲁卡因注射液在光和热同时作用下的稳定性  

Effect of light and heat on the stability of procaine hydrochloride injection

作　　者：林涛[1] 李琳丽[1] 詹先成[1] 李开兰[1] 李志毅[1] 殷恭宽[1] 

机构地区：[1]四川大学华西药学院物理化学教研室,成都610041

出　　处：《北京大学学报（医学版）》2001年第3期247-250,共4页Journal of Peking University:Health Sciences

基　　金：国家自然科学基金!(39770 882 )资助&&

摘　　要：目的 :以盐酸普鲁卡因注射液为例 ,研究药物在光和热同时作用下的稳定性。方法 :先考察该注射液在高温避光条件下的降解规律 ,求出热反应的降解速率常数kdark,指前因子Adark和活化能Ea ,dark,再在烘箱内上方分别安装荧光高压汞灯和紫外高压汞灯 ,考察其在高温和光照同时作用下的降解规律 ,求出光反应的降解速率常数klight,指前因子Alight和活化能Ea ,light。结果 :在高温光照试验中 ,该药物降解速率由两部分构成 :dAtotal/dt =kdark Adarkn′+klightAlightn,式中Atotal为盐酸普鲁卡因注射液在 44 0nm处的总吸收度 ,Adark和Alight分别为该药在无光照时热作用下所产生的吸收度和光作用下所产生的吸收度 (4 40nm ) ,n为光化反应的级数 ,n′为热反应的级数。光化反应速率仍与温度有关 :klight=Alight·exp(-Ea ,light/RT)·E ,式中E为光源的照度。结论 :由于klight的表达式与Arrhenius方程形式类似 ,式中Ea ,light可能为光化反应后继过程的表观活化能 ,由实验得出Ea ,light值几乎与光源种类无关而支持了这一观点 ;根据光和热同时对盐酸普鲁卡因注射液稳定性的影响规律 ,预测了该药物在室温。To study the effect of both light and heat on drug stability with procaine hydrochloride injection as a model. Methods: The degradation of the injection was studied at high temperatures in dark at first, and subsequently in light. The degradation rate constants k dark , and k light ; pre exponential factors A dark , and A light ; as well as the observed activation energies E a ,dark and E a ,light of the thermal reactions were obtained. The experiments in light were performed with a fluorescent mercury arc lamp or a UV mercury arc lamp installed at the top of the isothermal heating oven respectively. Results: Under the exposure to both light and high temperatures, the degradation of procaine hydrochloride was caused by both thermal and photo reactions. The total degradation rate could be divided into two parts: d A total /d t = k dark A dark n ′ + k light A light n , where A total is the total absorbance of procaine hydrochloride injection, A dark is the absorbance caused by heat, A light , the one caused by light, all at 440 nm and n is the rate order of the photo reaction, n ′ is the rate order of the thermal energy reaction. The k light can be expressed as: k light = A light ·exp(- E a ,light / RT )· E , where E is the illuminance of light. Conclusion: Since the k light equation is similar to the Arrhenius equation, it is suggested that E a ,light 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 E a ,light is independent of light sources. According to the rules observed, the shelf life of procaine hydrochloride injection in indoor daylight at room temperature is predicted.

关 键 词：盐酸普鲁卡因注射液 光作用 热作用 药物稳定性 

分 类 号：R971.2[医药卫生—药品]