Antimicrobial effectiveness of domestic timolol maleate eye drops / 中国药学杂志

ABSTRACT

OBJECTIVE: To screen out suitable antibacterial agent and reasonable dosage for timolol maleate eye drops. METHODS: According to the method of bacteriostatic effect test in Chinese Pharmacopoeia (Ch.P) 2015, the antimicrobial effectiveness of antimicrobial preservatives at different concentrations was tested to screen out the optimal agent and dosage. RESULTS: The eye drops added with ethyl hydroxybenzoate met the B-level requirements of bacteriostatic efficacy, which was the same as the sample without antibacterial agent, so ethyl hydroxybenzoate was not suitable as the antimicrobial preservative. The growth of five kinds of test microorganisms was inhibited effectively by 0.03 mg·mL-1 benzalkonium bromide. The timolol maleate eye drops with 0.03 mg·mL-1 benzalkonium bromide met the requirement of the quality standard. CONCLUSION: Benzalkonium bromide can be used as the antimicrobial preservative for timolol maleate eye drops.