Pharmacokinetics and aqueous humor penetration of levofloxacin 1.5% and moxifloxacin 0.5% in patients undergoing cataract surgery

PURPOSE: The objective of this study was to compare the pharmacokinetics of levofloxacin 1.5% and moxifloxacin hydrochloride 0.5% ophthalmic solutions in aqueous humor after multiple doses prior to cataract surgery. METHODS: Ninety-eight eyes underwent cataract surgery and met the requirements of PK analysis. Eligible eyes were randomly assigned in a 1:1 ratio to receive levofloxacin or moxifloxacin prior to cataract surgery and were randomized into one of four sampling time points (ie, 1, 2, 4, and 6 hour post-last dose). Randomization was investigator and laboratory-masked. Three days prior to cataract surgery, each patient instilled one drop of the assigned study medication into the operative eye four times daily. One aqueous humor specimen was collected from the eye at the randomized time point. Aqueous humor specimens were assayed for drug concentration using a validated liquid chromatography and tandem mass spectrometer. RESULTS: Concentrations of the drug in the aqueous humor, as described by mean C(max) and pooled AUC(0–6) values, were greater for levofloxacin than moxifloxacin (C(max): 1.43, 0.87 μg/ml, respectively, P=0.008; AUC(0–6) 6.1, 3.8 μg·min/ml, P<0.001 respectively). No treatment-emergent adverse events were reported. CONCLUSION: Significantly greater drug exposures were attained in aqueous humor following the administration of levofloxacin 1.5% than moxifloxacin 0.5% ophthalmic solution. Achieving considerable higher drug concentration in the aqueous humor with levofloxacin 1.5% may demonstrate a greater potential for bacterial eradication.