高效液相色谱法测定复方氯霉素乳膏含量及稳定性考察

目的测定复方氯霉素乳膏中氯霉素与醋酸地塞米松的含量，并考察温度对该乳膏含量稳定性的影响。方法采用高效液相色谱法，流动相为线性梯度洗脱：甲醇-0．34％磷酸二氢钾溶液（55：45）保持7min,8min～16min为（30：70），17min后恢复（55：45）。检洲波长240nm．流速1mL·min^-1，同时测定复方氯霉素乳膏中主药的含量，同时将乳膏在4℃、25℃和35℃下保存，在2d、7d、15d以及30d后分别取样测定含量，进而考察氯霉素、醋酸地塞米松在不同温度下的含量变化。结果新制品中氧霉素及醋酸地塞米松的含量分别为标示量的100．3％、100．0％。30d后只有在4℃下保存的样品含量达标。结论高效液相色谱法作为该制剂的质量控制方法方便、准确。氯霉素和醋酸地塞米松的含量均随汪度、时间的递增而递减。故须低温冷藏来保存本品。

Determination of the content and stability of compound chloramphenicol cream by HPLC

OBJECTIVE To determine the content of chloramphenicol and dexamethasone acetate in compound chloramphenicol cream and investigate the effect of temperature on its content stability. METHODS HPLC was used for the determination with the mobile phase consisted of methanol-0.34 % potassium dihydrogen phosphate buffer solution for linear gradient elution. First proportion of 55：45 for 7 minutes, then 30：70 for 8 minutes to 16 minutes and last return to 55 ： 45 after 17 minutes. The detecting wavelength was at 240nm, the flow rate was 1 mL·min^-1. These methods are applied to determine the eontent of chloramphenicol and dexamethasone acetate. Meanwhile the preparations was stored at 35℃,25℃ and 4℃, respectively. The content of chloramphenicol and dexamethasone acetate was determined at 2 days, 7 days, 15 days and 30 days. RESULTS The content of chloramphenicol and dexamethasone acetate in new preparation were 100.3 % and 100.0 % of their content marked, and only the ones which were stored at 4℃ were stable. CONCLUSION The method of HPLC which is using in quality control for this medicine is convenient and accurate. The content of chloramphenieot and dexamethasone acetate in the cream both decreased along with the increase of the temperature and the time. Therefore this compound preparation needs low temperature storage.