[Fortified antibiotic (vancomycin, amikacin and ceftazidime) eye drop stability assessment at -20 degrees C]

J Fr Ophtalmol. 2007 Oct;30(8):807-13. doi: 10.1016/s0181-5512(07)92614-5.
[Article in French]


Introduction: Fortified antibiotic ophthalmic solutions are regularly administered as an immediate treatment for bacterial keratitis. Fortified antibiotics used to be self-prepared by nurses. To solve this problem, pharmacy staff studied the stability of three 5% solutions of vancomycin, amikacin, and ceftazidime prepared in aseptic conditions from parenteral antibiotic solutions.

Material and methods: Solutions were frozen at -20 degrees C. Each solution were examined before storage and over a 75-day period. Ceftazidime and amikacin were diluted in 0.9% sodium chloride and vancomycin in 5% dextrose. Over a 75-day period, physical and pharmacological (absorbance spectra) properties and the sterility of each stock solution were studied.

Results: The pH of amikacin (6.51), ceftazidime (6.47), and vancomycin (3.77) remained stable during the 75-day period. Osmolarities also remained stable (367, 488, and 351 mOsm/L, respectively). There were no significant differences in the concentration, osmolarity, and pH of the three antibiotic solutions before storage and after 75 days of freezing. Over a 75-day period, the stability of amikacin, ceftazidime, and vancomycin remained constant; no contamination was detected before storage and after 75 days.

Conclusion: Topical fortified antibiotic solutions can be stored for 75 days at -20 degrees C (15 days quarantine). After this time, these eye-drops should be stored at 4 degrees C and should be discarded after 3 days.

Publication types

  • English Abstract

MeSH terms

  • Amikacin / chemistry*
  • Anti-Bacterial Agents / chemistry*
  • Ceftazidime / chemistry*
  • Drug Stability
  • Freezing
  • Ophthalmic Solutions / chemistry*
  • Vancomycin / chemistry*


  • Anti-Bacterial Agents
  • Ophthalmic Solutions
  • Vancomycin
  • Amikacin
  • Ceftazidime