OBJECTIVE To establish UHPLC method for the determination of six preservatives in sodium hyaluronate eye drops and assess their antimicrobial effectiveness, and to investigate the microbial contamination of multi-dose sodium hyaluronate eye drops without bacteriostatic agent.

METHODS The determination was performed on a C₁₈ column with mobile phases consisting of 0.1% phosphoric acid solution and 5% tetrahydrofuran methanol solution. The antibacterial efficacy of sodium hyaluronate eye drops were examined according to the antibacterial efficacy inspection method of Chinese Pharmacopoeia. The sodium hyaluronate eye drops without preservatives was simulated for daily use, and aseptic samples were taken within the validity period after opening for microbial inspection.

RESULTS The types and contents of preservatives in nine batches of samples from three manufacturers were consistent with the label, and the antibacterial efficacy met the regulations; the samples without preservatives showed no microbial growth within four weeks after opening.

CONCLUSION The method is simple, accurate and stable, and can be used for simultaneous determination of 6 preservatives in sodium hyaluronate eye drops. The content of preservatives in different enterprises varies greatly, and it is recommended that enterprises should investigate the minimum effective concentration of preservatives when screening prescriptions. Bacteria-resistant bottles can effectively prevent microbial contamination.