Turakka L, Ojanen T, Prittinen T
Pharmazie. 1986 Apr;41(4):254-6.
The reliability of the poured plate method for purity testing of three different creams and an anhydrous ointment was studied. The ability of some nonionic surfactants to elute the microbes from the semisolid preparations to water phase and possible detrimental effects of these surfactants on the microbes was especially investigated. The method was used to test the effect of preparation temperature and of storage on the number of microbes in creams. Nonionic surfactants studied did not generally harm the bacteria. Variation was, however, found between different bacterial species and even bacterial strains. The surfactants studied eluted bacteria quantitatively from the water-containing creams but not from the water-free ointment. The concentration needed for quantitative elution of microbes was dependent on the surfactant used, being lower for Brij 58 than for Tween 80. Heating of the phases up to 60 or 70 degrees C for a short time during the preparation of the creams does not ensure the microbial purity of the preparation. In creams made at 80 degrees C, however, all the bacteria had died, only the spores of B. subtilis survived this temperature. After two months storage at 5 degrees C, all microbes tested were still detected in creams. There were, however, differences in survival of different microbes. None of the bacteria multiplied during the storage, but decreased slightly in number.
研究了倾注平板法对三种不同乳膏和一种无水软膏进行纯度检测的可靠性。特别研究了一些非离子表面活性剂将半固体制剂中的微生物洗脱到水相中的能力，以及这些表面活性剂对微生物可能产生的有害影响。该方法用于测试制剂温度和储存对乳膏中微生物数量的影响。所研究的非离子表面活性剂一般不会损害细菌。然而，在不同细菌种类甚至菌株之间发现了差异。所研究的表面活性剂能从含水乳膏中定量洗脱细菌，但不能从无水软膏中洗脱。定量洗脱微生物所需的浓度取决于所用的表面活性剂，Brij 58所需的浓度低于吐温80。在乳膏制备过程中，将各相短时间加热至60或70摄氏度并不能确保制剂的微生物纯度。然而，在80摄氏度制备的乳膏中，所有细菌均已死亡，只有枯草芽孢杆菌的孢子能在该温度下存活。在5摄氏度储存两个月后，在乳膏中仍能检测到所有测试的微生物。然而，不同微生物的存活情况存在差异。储存期间没有细菌繁殖，但数量略有减少。
