Stability and antibacterial activity in vitro of temporary preparation ceftazidime and vancomycin eyedrops / 中国生化药物杂志

ABSTRACT

Objective To study the stability and antibacterial activity in vitro of temporary preparation ceftazidime and vancomycin eyedrops respectively under different storage temperatures and light conditions.Methods Solutions of ceftazidime 50 mg/mL and vancomycin 50 mg/mL were prepared by reconstituting with balanced salt solution ( BSS) and stored at 4℃ and 24℃with and without exposure to light, respectively.Changes in pH values and physical characteristics of the solutions were recorded and minimum bactericidal concentrations against P.aeruginosa and S.aureus were measured at 0, 3, 7, 14, 21 and 28d respectively.Results The antibacterial potency of ceftazidime decreased significantly from days 3 and 7 at storage temperatures of 24℃ and 4℃, respectively, but was not affected by light exposure.The pH value progressed from acidic to alkaline, reached maxium value at 3 day, in all solutions.The antibacterial potency of vancomycin remained stable during the four-week period, but its pH increased showed that acidity decreased.Conclusion Ceftazidime eyedrops in BSS appears to remain effective against P.aeruginosa 7 days above when stored at 4℃, but are less effective when stored at 24℃.The degradation was observed using the color changes of ceftazidime solution and its physical properties, which should be pay attention to the suddenly rise in the 3rd day, however, as it may affect patients’tolerance.Vancomycin eyedrops in BSS can be safely used for 4 weeks above, stored at either 4℃ or 24℃.