ABSTRACT
Objective To establish a microbial limit examination method and a verified methodology for diluted benzalkonium bromide solution , and ensure the effectiveness of the method .Methods Microbial limit test of diluted benzalkonium bromide solution was used as the validation methodology according to the validation test requirements of appendix XI J of the second version of the “Chi-nese Pharmacopoeia” published in 2010.Results Membrane filtration method could be used for counting bacteria , mold and yeast count in the microbial limit examination of the diluted benzalkonium bromide solution;membrane filtration method could be adopted to control the bacteria .Conclusion Antibacterial activity of diluted benzalkonium bromide solution should be fully considered before ex -amination when building its examination method through microbial limit methodology validation .