Intraocular penetration of sequentially instilled topical moxifloxacin, gatifloxacin, and levofloxacin

Koji Sugioka1, Masahiko Fukuda1, Shohei Komoto1, Motoki Itahashi1, Masakazu Yamada2, Yoshikazu Shimomura11Department of Ophthalmology, Kinki University School of Medicine, Osaka-Sayama City, Osaka, Japan; 2Division for Vision Research, National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo, JapanPurpose: The objective of the study was to compare the intraocular penetration levels of the newer fluoroquinolones, moxifloxacin, gatifloxacin, and levofloxacin in the rabbit’s cornea, aqueous humor, and conjunctiva after topical instillation.Methods: 0.5% moxifloxacin, 0.3% gatifloxacin, and 0.5% levofloxacin were instilled in random sequence in both eyes of nine New Zealand White rabbits at two-minute intervals. Instillation was repeated every 15 minutes for a total of three drops of each fluoroquinolone per eye. Three additional animals had only moxifloxacin instilled bilaterally using the same schedule. Sixty minutes after the final instillation, the rabbits were sacrificed for determination of corneal, aqueous humor, and conjunctival fluoroquinolone concentrations using highperformance liquid chromatography.Results: Moxifloxacin achieved significantly higher concentrations than levofloxacin and gatifloxacin in the cornea (P = 0.0102 and P = 0.0006, respectively), aqueous humor (P = 0.0015 and P < 0.0001, respectively), and conjunctiva (P = 0.0191 and P = 0.0236, respectively). Conclusions: 0.5% moxifloxacin eyedrops provided superior intraocular penetration in rabbits’ eyes compared with the two other fluoroquinolones, 0.5% levofloxacin and 0.3% gatifloxacin.Keywords: fluoroquinolone, gatifloxacin, levofloxacin, moxifloxacin, penetration, rabbit