title: Effects of dehydration on corneal tissue absorption of topical azithromycin in rabbits.
abstract: OBJECTIVE
  To assess the corneal tissue absorption of azithromycin in desiccated and normal eyes of rabbits.
  
  
  METHODS
  A total of 25 New Zealand Albino rabbits weighing 2-3 kg each were included. One eye of each rabbit was desiccated. The other eye was left as control. Azithromycin 1.5% topical eyedrops were instilled in both eyes. Five rabbits were sacrificed at each of the following time points: 30 min, 3 hr, 6 hr, and 12 hr. Corneal tissues specimens were subjected to high-performance liquid chromatography mass spectrometry. A paired t test was used to evaluate the statistical difference in corneal tissue absorptions of azithromycin at each time point.
  
  
  RESULTS
  The mean corneal tissue levels of azithromycin in dry eyes were 66.3 microg/ml, 92.6 microg/ml, 117.5 microg/ml, and 179.9 microg/ml, and the mean corneal tissue levels of azithromycin in normal eyes were 42.0 microg/ml, 43.4 microg/ml, 43.3 microg/ml, and 80.0 microg/ml at 30 min, 3 hr, 6 hr, and 12 hr respectively. Both groups showed increase in corneal tissue absorption overtime (p < 0.0001). Significantly higher levels of azithromycin were noted in dry eyes at each time point except at the 30-min time point.
  
  
  CONCLUSIONS
  This study demonstrated that corneas exposed to desiccation showed statistically significant increase in azithromycin level compared to normal eyes.
authors.affiliation: The Eye Center and The Eye Foundation for Research in Ophthalmology, Riyadh, Saudi Arabia. k.tabbara.nesma.net.sa
authors.forename: Khalid F
authors.initials: KF
authors.lastname: Tabbara
authors.forename: Amgad A
authors.initials: AA
authors.lastname: Kotb
authors.forename: Ehab F
authors.initials: EF
authors.lastname: Hammouda
authors.forename: Naser
authors.initials: N
authors.lastname: Elkum
mesh_terms: D000042:Absorption; D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D017963:Azithromycin / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D003315:Cornea / Q000378:metabolism*; D003890:Desiccation; D005260:Female; D008297:Male; D011817:Rabbits; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin