Abstract
Purpose: :
Besifloxacin is a novel fluoroquinolone antibiotic in clinical development for the treatment of bacterial conjunctivitis. Information for the direct evaluation of the in vivo efficacy of besifloxacin with other commonly marketed fluoroquinolones is currently unavailable. The present study was designed to compare the ocular and systemic pharmacokinetics of besifloxacin with moxifloxacin (Vigamox®) and gatifloxacin (Zymar®) following topical ocular administration to pigmented rabbits.
Methods: :
Dutch Belted rabbits (32/group) were arbitrarily assigned to one of the three dose groups: Group 1: Vigamox® (moxifloxacin HCl, 0.5%), Group 2: Zymar® (gatifloxacin, 0.3%), Group 3: Besifloxacin, (0.6%). Animals received a single instillation of 50-µL/eye of the appropriate formulation. Ocular tissue and plasma samples were collected at various intervals up to 24 hr after instillation. Drug concentrations were determined by LC/MS/MS.
Results: :
All fluoroquinolones exhibited rapid absorption following topical ocular administration (Tmax ≤ 1 hr). Maximal concentrations of besifloxacin in tears and conjunctiva were generally higher when compared with those obtained with moxifloxacin or gatifloxacin; while concentrations in cornea were comparable for all three compounds. Systemic exposure to besifloxacin was found to be considerably lower when compared with the other fluoroquinolones.
Conclusions: :
Besifloxacin achieved higher exposure in target ocular tissues when compared with moxifloxacin or gatifloxacin. The promising pharmacokinetic behavior of besifloxacin, together with its broad antibacterial potency against the major ocular pathogens supports the ongoing clinical development of this compound.
Keywords: antibiotics/antifungals/antiparasitics • conjunctivitis • bacterial disease