Purpose:
To compare fluoroquinolone concentrations in rabbit corneasfollowing administration of Iquix® (1.5% levofloxacin, LEV),Vigamox® (0.5% moxifloxacin, MOX), or Zymar® (0.3% gatifloxacin,GAT).
Methods:
Rabbits were randomized to receive a single drop bilaterallyof commercial ophthalmic fluoroquinolone formulations: Iquix(N=21), Vigamox (N=21), or Zymar (N=21). Three animals in eachgroup were sacrificed at 10 or 30 minutes or at 1, 2, 4, 8,or 12 hours post-dosing. Cornea samples (n=6 per time point)were collected and analyzed using a validated method. Mean tissueconcentrations were calculated for each time point. Drug exposuremeasured as area under the curve (AUC) from time of dosing wascalculated by the linear trapezoid method.
Results:
LEV and MOX penetrated cornealtissue more quickly than GAT.MOX was cleared morequickly than LEV or GAT. MOX was below detectablelimitsafter 4 hrs; GAT was below detectable limits by12 hrs. LEV concentrationswere higher than those ofMOX and GAT at all time points andwas the onlyfluoroquinolone in quantifiable concentrations at12hrs. Due to differences in pharmacokinetics, drugexposure(AUC) to LEV was more than 2-fold greaterthan to MOX or GAT
Conclusions:
The kinetics of drug penetrationand clearance in corneal tissuediffer for Iquix,Vigamox, and Zymar. A single drop of Iquixprovideshigher and more persistent fluoroquinoloneconcentrationsin corneal tissue than Vigamox orZymar.
Keywords: antibiotics/antifungals/antiparasitics • cornea: epithelium • cornea: stroma and keratocytes