6 % administered Fosbretabulin ic50 TID for 5 days in the treatment of bacterial conjunctivitis, eradication rates were already very high at Day 4/5 (91.5 % for besifloxacin vs. 59.7 % for vehicle [14]; 93.3 % for besifloxacin vs. 91.1 % for moxifloxacin [15]; and 90.0 % for besifloxacin vs. 46.6 % for vehicle [13], demonstrating the rapid effect of besifloxacin treatment; these bacterial eradication rates were also associated with rapid improvements in the clinical signs and symptoms of acute bacterial conjunctivitis. It follows that although the earliest time point of bacterial eradication assessment in this study was Day 8, it is likely that high bacterial eradication rates were
achieved much earlier. In the present study, similar bacterial eradication rates were seen at Days 8 and 11 for Gram-positive (82.8 and 84.3 %, respectively) and Gram-negative Salubrinal in vitro species (91.1 and 89.6 %, respectively) in besifloxacin-treated eyes. Bacterial eradication rates with vehicle were
lower on Days 8 and 11 for both Gram-positive (38.3 and 54.8 %, respectively) and Gram-negative species (71.4 and 75.9 %). The most common bacterial species isolated at baseline in order of prevalence were S. epidermidis, H. influenzae, 5-Fluoracil ic50 S. aureus, and S. mitis group. As expected, bacterial eradication rates for these species also appeared better with besifloxacin treatment compared with vehicle treatment. It deserves mention that the besifloxacin ophthalmic suspension 0.6 % formulation contains
the preservative benzalkonium chloride (BAK) at a concentration of 0.01 %. The presence of BAK in topical ophthalmic formulations has been shown to have dose-dependent conjunctival and corneal epithelial cell toxicity [23–26], although the clinical relevance of this phenomenon in routine clinical practice, especially with short-term usage, Epothilone B (EPO906, Patupilone) is not yet clear. The very low rate of adverse effects noted in the current study does not suggest any toxicity risk with the concentration of BAK present in the besifloxacin suspension formulation. BAK has also been shown to possess inherent bacteriostatic and bactericidal activities [27, 28]; thus, it is possible that BAK contributed to the bacterial eradication rate observed in both the besifloxacin treatment group and vehicle group in the present study, as both treatments contained BAK at a concentration of 0.01 %. Since the present study did not include an additional control group without BAK, any possible confounding of bacterial eradication rates from the inclusion of BAK cannot be fully evaluated. In conclusion, the results of this analysis expand upon those previously identified using besifloxacin ophthalmic suspension 0.6 % for 5 days. These new data indicate that besifloxacin ophthalmic suspension 0.6 % is safe for use in patients aged 1 year and older with bacterial conjunctivitis when used TID for 7 days, while providing high bacterial eradication rates.