Pharmacokinetics of topically applied ciprofloxacin in tears of mesocephalic and brachycephalic dogs.
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.
Hendrix
Diane V H
DV
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996-4544, USA. dhendrix@utk.edu
Cox
Sherry K
SK
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
D000890:Anti-Infective Agents; D009883:Ophthalmic Solutions; D002939:Ciprofloxacin