Aqueous penetration of moxifloxacin 0.5% ophthalmic solution and besifloxacin 0.6% ophthalmic suspension in cataract surgery patients.

To determine the aqueous humor concentrations of moxifloxacin and besifloxacin after routine preoperative topical dosing in patients having cataract surgery.Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, USA.In this prospective randomized parallel double-masked clinical trial, 1 drop of commercially available moxifloxacin 0.5% ophthalmic solution or besifloxacin 0.6% ophthalmic suspension was administered every 10 minutes for a total of 4 doses beginning 1 hour before routine cataract surgery. Aqueous humor was sampled via the paracentesis, and antibiotic concentrations were determined using validated high-performance liquid chromatography procedures.The study enrolled 50 patients. The aqueous concentration of the antibiotic agent was detectable in all 23 moxifloxacin samples and in 10 (40%) of the 25 besifloxacin samples (P<.0001, Pearson chi-square test). The mean aqueous concentration in the moxifloxacin samples was 50-fold higher than in the besifloxacin samples (1.6108 microg/mL versus 0.0319 microg/mL) when all samples were included (P<.0001, Wilcoxon test), while the moxifloxacin concentration was 38-fold higher than the besifloxacin concentration (1.6108 microg/mL versus 0.0422 microg/mL) in the samples with detectable antibiotic agent (P<.0001).After topical preoperative administration, moxifloxacin 0.5% ophthalmic solution had a 38-fold to 50-fold higher concentration in the aqueous humor than besifloxacin 0.6% ophthalmic suspension. Besifloxacin was undetectable in more than half the aqueous humor samples.