Studies on Antimicrobial Preservatives Screening and Antimicrobial Efficacy of Diclofenac Sodium Eye Drops / 中国药学杂志

ABSTRACT

OBJECTIVE: To evaluate the bacteriostatic efficacy of diclofenac sodium eye drops and to explore the reasonable dose of benzalkonium chloride, ethylparaben and thimerosal in diclofenac sodium eye drops. METHODS: According to the method of bacteriostatis effect test in 2015 edition of Chinese Pharmacopoeia (Ch.P),and Escherichia coli, Staphylococcus aureus, Pesudomonas aeruginosa, Candida albicans and Aspergillus niger as test strains,the bacteriostatis effect of diclofenac sodium eye drops from 10 batches of the samples was determined. Also, the concentration gradient of benzalkonium chloride, ethylparaben and thimerosal in diclofenac sodium eye drops was designed to investigate the optimum bacteriostatic concentration. RESULTS: The samples from 3 manufacturers could reach level B, no sample could reach level A,and those from 7 manufacturers did not comply with the specification. When the concentration of thimerosal was 0.01 mg•mL-1 and the concentration of ethylparaben was 0.3 mg•mL-1 in diclofenac sodium eye drops, the bacteriostatic efficacy could reach level B. When the concentration of benzalkonium chloride was 0.01 mg•mL-1, the bacteriostatic efficacy could reach level A. CONCLUSION: The bacteriostatis effect of diclofenac sodium eye drops from 10 batches of the samples is not good, It is recommended that these manufacturers should optimize the type and concentration of antimicrobial agents and optimize their formulation based on both biological tests and physical-chemical tests to ensure drug safety.