Studies on Test for Sterility of β-Lactam Antibiotics

OBJECTIVE To establish methods to detect the microbial contamination of β-lactam antibiotics. METHODS Membrane filtration method was used by modifying the amount of rinsing fluid and adding β-lactamase to inactivate the antibiotic. RESULTS All of positive strains and test strains revealed growth of microorganism in two days and the substance control and negative control gave no evidence of growth. CONCLUSION β-lactam antibiotics, whatever the kind or specification, can be dissolved into about 20 mg·mL-1 and then we can do its sterility test according to membrane filtration method. Adding some β-lactamase in thioglycollate medium for the antibiotics which are sensitive to it can decrease the amount of rinsing fluid and the most effective sterility test method is gained.