油脂类乳膏药品萃取后微生物在油相与水相中的分布状况研究

Distribution of microorganisms in oil and aqueous phase of grease cream drugs after extraction

目的:通过研究萃取后5种不同类型微生物在油相和水相的分布规律,探讨萃取法在非无菌药品微生物限度检查时油脂类供试液制备中的应用。方法:在无菌的十四烷酸异丙酯-pH 7.0氯化钠蛋白胨缓冲液(v/v,1∶1)中分别接种高、低浓度的金黄色葡萄球菌、铜绿假单胞菌、枯草芽孢杆菌、白色念珠菌和黑曲霉等5种试验菌,混匀静置5 min,照《中华人民共和国药典》2015年版四部1105的方法进行计数检查,计算回收率。应用水分活度测定仪分别测定油相、水相的水分活度(a_w)。对油脂类乳膏剂用萃取法处理,然后薄膜过滤进行计数方法适用性试验。结果:萃取后不同浓度、不同类型的试验菌主要分布在下层水相中,各试验菌回收率均在0.5%～2.0%之间。25℃下油相a_w为0.22,水相a_w为0.99。3种乳膏剂试验菌回收率均在0.5%～2.0%之间。结论:萃取后微生物在油相、水相中非均匀分布,其主要分布特点是微生物趋向于分布在有利于其生存的环境条件水相中。采用十四烷酸异丙酯萃取的方法可用于油脂类乳膏药品微生物限度检查时的供试液制备。

Objective:To study the distribution of 5 different kinds of microorganisms in the oil phase and aqueous phase after extraction,discuss the application of extraction method in the preparation of fatty sample solution for microbiological examination of non-sterile products.Methods:Low and high concentrations of test microorganism which included Staphylococcus aureus,Pseudomonas aeruginosa,Bacillus subtilis,Candida albicans,Aspergillus nigerin were inoculated respectively in sterile isopropyl myristate and pH 7.0 sodium chloride peptone buffer(v/v,1∶1).The samples were mixed and laid for 5 minutes.The recovery rate was calculated according to the method of ChP 2015 edition Volume Ⅳ<1105>counted inspection.Water activity instrument was used to determine water activity of oil phase and aqueous phase respectively.The extraction method was adopted to deal with fatty cream samples,and the method suitability experiments were completed with membrane filter.Results:Different concentrations and different types of microorganisms were mainly distributed in aqueous phase after extraction,the recovery rates of each tested microorganism were 0.5 to 2.0.Water activity(a_w)of oil phase was 0.22 and aqueous phase was 0.99 at 25 ℃.The test bacteria recovery rates of 3 kinds of grease cream drugs were between 0.5 to 2.0.Conclusion:Microorganisms after extraction distributed inhomogeneous in oil and aqueous phase.Its main distribution characteristic is that the microorganisms tend to be distributed in the aqueous phase where is favorable for their survival.The method of extracting with isopropyl myristate could be used to prepare the test solution for microbial limit test for oil and fat samples.