Comparative penetration of moxifloxacin and gatifloxacin in rabbit aqueous humor after topical dosing.
OBJECTIVE
To evaluate the aqueous penetration of the fourth-generation fluoroquinolones moxifloxacin and gatifloxacin.


METHODS
University of Arizona, Tucson, Arizona, USA.


METHODS
Forty eyes of 20 New Zealand white rabbits were divided into 2 experimental groups. In Experiment I rabbits (20 eyes), a commercial preparation of topical gatifloxacin 0.3% was administered to 9 eyes and moxifloxacin 0.5% to 9 eyes; 2 eyes served as a control. Eyes were dosed according to a keratitis protocol; ie, every 15 minutes for 4 hours. The aqueous humor was sampled 10 minutes after the last dose. Experiment II rabbits (20 eyes) were dosed according to a cataract prophylaxis protocol; ie, 4 times a day for 10 days. The aqueous humor was sampled 1 hour after the last dose of antibiotic in 12 eyes and 24 hours after the last dose in 8 eyes. High-performance liquid chromatography was used to determine the fluoroquinolone concentration.


RESULTS
In the keratitis dosing protocol, the mean concentration of moxifloxacin in the aqueous (n=9) was 11.057 microg/mL (range 7.66 to 18.87 microg/mL), which was significantly higher than the mean concentration of gatifloxacin (n=8) (7.570 microg/mL [range 4.75 to 10.86 microg/mL]) (P=.030). In the cataract prophylaxis dosing protocol, the mean aqueous concentration of moxifloxacin (n=6) was 1.745 microg/mL (range 0.92 to 3.87 mg/mL). The mean concentration of gatifloxacin (n=6) was 1.207 microg/mL (range 0.44 to 2.44 microg/mL). The difference was not statistically significant (P=.359).


CONCLUSIONS
Higher mean levels (x1.46) of aqueous penetration were achieved with moxifloxacin than with gatifloxacin in the keratitis-dosing model. There was no statistically significant difference between the 2 drugs in the cataract prophylaxis dosing model. Both antibiotics had aqueous levels in excess of the minimum inhibitory concentration for most pathogenic organisms in both models.
Levine
Jason M
JM
University of Arizona, Department of Ophthalmology, Tucson, AZ, USA.
Noecker
Robert J
RJ
Lane
Lisa C
LC
Herrygers
Lisa
L
Nix
David
D
Snyder
Robert W
RW
D000287:Administration, Topical; D000818:Animals; D000890:Anti-Infective Agents / Q000493:pharmacokinetics*; D001082:Aqueous Humor / Q000378:metabolism*; D001372:Aza Compounds / Q000493:pharmacokinetics*; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D003315:Cornea / Q000378:metabolism; D024841:Fluoroquinolones / Q000493:pharmacokinetics*; D000077734:Gatifloxacin; D000077266:Moxifloxacin; D009883:Ophthalmic Solutions; D011804:Quinolines / Q000493:pharmacokinetics*; D011817:Rabbits
D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D009883:Ophthalmic Solutions; D011804:Quinolines; D000077734:Gatifloxacin; D000077266:Moxifloxacin