Abstract: In order to establish an sterility test method for ceftiofur hydrochloride intramammary infusion,the sampling amount,diluent type,washing method and enzyme dosage were investigated in accordance with the relevant requirements of the method suitability test in appendix 1101 of Chinese Veterinary Pharmacopoeia 2015 edition.Samples were placed in a sterile funnel,isopropyl tetradecanoate was added to the funnel,the 0.1% sterile peptone solution containing 1% polysorbide 80 was added to the funnel,the water layer was shaken and placed quietly,the water was taken out and treated by membrane filtration and the pH 7.0 sterile sodium chloride-peptone buffer solution was used as the washing solution.Each filter membrane was washed four times with a washing capacity of 100 mL.Penicillinase solution of not less than 6 million units was added to each tube of culture medium.The results showed that the six positive bacteria test groups grew as well as the positive bacteria control group,the test group and the negative control group grew aseptically.These indicated that the test quantity of the test samples had eliminated its bacteriostasis under the test conditions.Ceftiofur hydrochloride had strong bacteriostasis activity.In this experiment,a reasonable method of sterility test was established by membrane filtration method,which could effectively remove the bacteriostasis ingredients in ceftiofur hydrochloride intramammary infusion and make the test results more accurate and reliable.It could be used as a routine aseptic test method for the preparation.

Key words: ceftiofur hydrochloride intramammary infusion; sterility test; membrane filtration; method applicability test