Abstract
Abstract: :
Purpose: To determine moxifloxacin, gatifloxacin, ofloxacin and ciprofloxacin concentrations in conjunctival tissue 20 minutes following instillation of a single dose. Methods: Patients underwent baseline screening and slit lamp examinations. Moxifloxacin 0.5%, gatifloxacin 0.3%, ofloxacin 0.3% or ciprofloxacin 0.3% was instilled in the study eye 20 minutes prior to biopsy according a pre–defined randomization scheme. Two conjunctival biopsies (1 temporal and 1 nasal from the inferior cul de sac) were taken from the study eye, and all subjects were followed for 1 week. Samples were analyzed by a dual analyte reversed phase HPLC method. Results: After a single administration of either moxifloxacin (n = 15), gatifloxacin (n = 14), ofloxacin (n = 13) or ciprofloxacin (n = 12), the conjunctival concentrations (µg/g ± std. dev.) were 18.0 (± 16.4), 2.54 (± 2.99), 1.26 (± 0.88) and 2.65 (± 2.01), respectively. The mean conjunctival concentration of moxifloxacin was 6.8–fold higher than that observed for ciprofloxacin, 7.1–fold higher than for gatifloxacin and 14.3–fold higher than for ofloxacin. These differences were statistically significant (P < 0.0001). There was not a statistically significant difference between the conjunctival concentrations of the other three fluoroquinolones. Conclusions: The biopsy and analytical methods used in this study represent a novel, safe and accurate technique for obtaining conjunctival tissue antibiotic concentrations. Moxifloxacin 0.5% ophthalmic solution achieved significantly greater target tissue penetration than gatifloxacin, ofloxacin or ciprofloxacin. Enhanced penetration may result from moxifloxacin’s high biphasic solubility (both lipophilic and aqueous solubility). Moxifloxacin’s conjunctival depot effect may enhance treatment of bacterial conjunctivitis compared with other fluoroquinolones.
Keywords: antibiotics/antifungals/antiparasitics • conjunctiva • conjunctivitis