title: Pharmacokinetics of topically applied ciprofloxacin in tears of mesocephalic and brachycephalic dogs.
abstract: OBJECTIVE
  To evaluate the pharmacokinetics of ophthalmic ciprofloxacin in the tear film of normal mesocephalic and brachycephalic dogs.
  
  
  METHODS
  Twenty mesocephalic dogs and 15 brachycephalic dogs.
  
  
  METHODS
  Thirty-five microliters of ciprofloxacin were placed on the cornea of both eyes of each dog. Five brachycephalic dogs were used twice. A tear-test strip placed in the ventral cul de sac for 30 s was used to obtain samples. The tear film of each eye was sampled once at eight time-points post administration, resulting in five samples at each time-point. Samples were evaluated using high performance liquid chromatography. Data from the two skull types were compared using the unpaired two-tailed t-test.
  
  
  RESULTS
  The mean concentration of ciprofloxacin in the tears of mesocephalic dogs was 192.8 +/- 269.97, 140.6 +/- 91.06, 56.60 +/- 28.47, 13.6 +/- 6.3, 43.25 +/- 59.71, 16.6 +/- 10.62, 15.6 +/- 13.16 and 6.25 +/- 9.84 microg/g at 5, 10, 15, 30 min and 1, 2, 4 and 6 h, respectively. The mean concentration of ciprofloxacin in the tears of brachycephalic dogs was 272.6 +/- 106.21, 144.4 +/- 142.32, 131.2 +/- 147.07, 75 +/- 80.07, 40.8 +/- 30.35, 35 +/- 21.98, 52.75 +/- 51.87 and 8.6 +/- 12.10 microg/g at 5, 10, 15, 30 min and 1, 2, 4 and 6 h, respectively. There was no statistical difference in tear concentration at any time-point between skull types.
  
  
  CONCLUSIONS
  Topical application of ciprofloxacin resulted in a mean tear concentration of ciprofloxacin that remained above the MIC(90) levels for most pathogenic bacteria for 6 h in normal mesocephalic and brachycephalic dogs.
authors.affiliation: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996-4544, USA. dhendrix@utk.edu
authors.forename: Diane V H
authors.initials: DV
authors.lastname: Hendrix
authors.forename: Sherry K
authors.initials: SK
authors.lastname: Cox
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004285:Dogs / Q000378:metabolism*; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000493:pharmacokinetics; D013666:Tears / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D009883:Ophthalmic Solutions; D002939:Ciprofloxacin