title: [Fortified antibiotic (vancomycin, amikacin and ceftazidime) eye drop stability assessment at -20 degrees C].
abstract: BACKGROUND
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Pharmacie Hospitalière, Centre Hospitalier Universitaire, Caen. chedru-v@chu-caen.fr
authors.forename: V
authors.initials: V
authors.lastname: Chédru-Legros
authors.forename: M
authors.initials: M
authors.lastname: Fines-Guyon
authors.forename: A
authors.initials: A
authors.lastname: Chérel
authors.forename: A
authors.initials: A
authors.lastname: Perdriel
authors.forename: F
authors.initials: F
authors.lastname: Albessard
authors.forename: D
authors.initials: D
authors.lastname: Debruyne
authors.forename: F
authors.initials: F
authors.lastname: Mouriaux
mesh_terms: D000583:Amikacin / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002442:Ceftazidime / Q000737:chemistry*; D004355:Drug Stability; D005615:Freezing; D009883:Ophthalmic Solutions / Q000737:chemistry*; D014640:Vancomycin / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D009883:Ophthalmic Solutions; D014640:Vancomycin; D000583:Amikacin; D002442:Ceftazidime