Conjunctival Concentrations of a New Ophthalmic Solution Formulation of Moxifloxacin 0.5% in Cataract Surgery Patients

To compare the conjunctival concentrations of moxifloxacin after instillation of a single drop of moxifloxacin ophthalmic solution, 0.5% (Moxi) or a new 0.5% ophthalmic solution formulation (MAF) containing a retention-enhancing agent in patients undergoing cataract surgery. This was a randomized, double-masked, parallel-group study. One hundred thirty patients scheduled for routine phacoemulsification and intraocular lens implantation were randomized to both treatment and post-dose sample collection time points. A single topical drop of Moxi or MAF was instilled in the study eye. At the designated time (0.25, 0.5, 1, 3, or 5 h post-dose), 2 conjunctival biopsy samples were obtained (N = 11-13 per treatment condition). Concentrations of moxifloxacin were determined using a validated ultra-performance liquid chromatography method. Moxifloxacin exposure [maximum mean moxifloxacin concentrations (C(max)) and area under the concentration-time curve (AUC)] was estimated from the observed concentration-time data. The conjunctival moxifloxacin C(max), 43.8 μg/g, for MAF was achieved at 0.25 h. This was 1.8-fold higher than the C(max) for Moxi (24.1 μg/g), which was reached at 0.5 h post-dose. MAF AUC(0-3) was significantly greater than the AUC(0-3) of Moxi [50.5 (μg·h)/g vs. 27.1 (μg·h)/g; P