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 mu g/0.1 mL were compounded and prepared in 1-mL polypropylene syringes and stored at 4 degrees C, -20 degrees C, and -80 degrees 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 degrees 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 degrees C or -80 degrees C. The results of this study may have important implications for the current management of endophthalmitis. RETINA 31: 1316-1322, 2011