RESUMEN
OBJECTIVE: To carry out standardization research on pre-filtration method for microbial test solutions of drugs and establish a new double-membrane filtration method in microbial tests. METHODS: New filters with double-membranes of different materials or pore-sizes were designed and used as pre-filters for microbial tests. The effects of test solution pre-filtration on several wild-type strains were evaluated and compared with the methods described by Chinese Pharmacopoeia. RESULTS: No statistical difference was found between the double-membrane filtration method and the pharmacopoeia method. However, filter-clogging was significantly reduced by using the double-membrane filtration method, and the double-membrane filtration method could also eliminate the antibacterial activity of the samples, thus reducing the damage or loss of microorganisms in special samples. CONCLUSION: The double-membrane filtration method meets the requirements of the Chinese Pharmacopoeia; the test results are valid and the method can be used for sterility test and microbial limit test for drug products.