Long-term potency, sterility, and stability of vancomycin, ceftazidime, and moxifloxacin for treatment of bacterial endophthalmitis

Purpose To determine the long-term potency, sterility, and stability of vancomycin, ceftazidime, and moxifloxacin prepared in single-use polypropylene syringes for intravitreal injection. Methods Experimental study. Vancomycin 1 mg/0.1 mL, ceftazidime 2 mg/0.1 mL, and moxifloxacin 160 μg/0.1 mL were compounded and prepared in 1-mL polypropylene syringes and stored at 4 °C, -20 °C, and -80 °C. Antibiotic potency, sterility, pH, osmolality, and concentration were tested at baseline and at 1, 2, 4, 8, 12, and 24 weeks after preparation. Results Potency, sterility, and stability were preserved for all 3 antibiotics at all temperatures out to 24 weeks, although there was a trend toward reduced potency at Week 24 for vancomycin and ceftazidime stored at 4°C. The largest zones of inhibition for Staphylococcus epidermidis and S. aureus were consistently demonstrated by moxifloxacin. Conclusion Vancomycin, ceftazidime, and moxifloxacin prepared in single-use polypropylene syringes retain potency, sterility, and stability out to 24 weeks when stored at -20 °C or -80 °C. The results of this study may have important implications for the current management of endophthalmitis.