title: Comparative intraocular penetration of 4 fluoroquinolones after topical instillation.
abstract: OBJECTIVE
  To compare the intraocular penetration of 4 fluoroquinolone eye drops after topical instillation into rabbit eyes.
  
  
  METHODS
  The tested drugs were levofloxacin 1.5% (LVFX), gatifloxacin 0.3%, moxifloxacin 0.5% (MFLX), and besifloxacin 0.6% (BFLX). Forty-eight New Zealand white rabbits were randomly assigned into 2 groups. For group 1 (40 rabbits, 80 eyes), single instillation was performed, and tissue samples were acquired after 0.5, 1, 2, 4, and 6 hours. For group 2 (8 rabbits, 16 eyes), repeated instillation was performed (4 times, every 15 minutes), and tissues were acquired 1 hour after the fourth instillation. The drug concentrations in ocular tissues (cornea, aqueous, conjunctiva, and trisected vitreous) were analyzed with high-performance liquid chromatography.
  
  
  RESULTS
  The AUC 0-6 h (area under the curve, in microgram.hour/gram) in group 1 and the mean concentration (in micrograms/gram) in group 2 for LVFX, gatifloxacin 0.3%, MFLX, and BFLX, respectively, were 22.97, 6.44, 13.54, and 3.29 and 22.60, 6.99, 13.69, and 1.91 in cornea; 5.66, 1.43, 3.38, and 0.42 and 5.52, 1.29, 2.47, and 0.19 in aqueous humor; 2.33, 0.91, 2.17, and 9.83 and 4.51, 0.78, 1.48, and 2.09 in bulbar conjunctiva; 0.243, 0.051, 0.134, and 0.018 and 0.182, 0.055, 0.122, and 0.015 in anterior vitreous; none of the drugs achieved enough concentration in equatorial and posterior vitreous. Repeated instillation resulted in approximately 2.1 times greater penetration than single instillation.
  
  
  CONCLUSIONS
  LVFX and MFLX demonstrated good intraocular penetration particularly in cornea, aqueous humor, and anterior vitreous, and they may be considered the penetrative fluoroquinolones. BFLX showed high concentration in bulbar conjunctiva and may be considered the retentive fluoroquinolone.
authors.affiliation: Myung-Gok Eye Research Institute, Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, Seoul, South Korea.
authors.forename: Jae Lim
authors.initials: JL
authors.lastname: Chung
authors.forename: Eun Hye
authors.initials: EH
authors.lastname: Lim
authors.forename: Sang Wroul
authors.initials: SW
authors.lastname: Song
authors.forename: Byung Yeop
authors.initials: BY
authors.lastname: Kim
authors.forename: Joon H
authors.initials: JH
authors.lastname: Lee
authors.forename: Francis S
authors.initials: FS
authors.lastname: Mah
authors.forename: Kyoung Yul
authors.initials: KY
authors.lastname: Seo
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001082:Aqueous Humor / Q000378:metabolism*; D019540:Area Under Curve; D001372:Aza Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics; D001381:Azepines / Q000008:administration & dosage / Q000493:pharmacokinetics; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D003228:Conjunctiva / Q000378:metabolism*; D003315:Cornea / Q000378:metabolism*; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000077734:Gatifloxacin; D064704:Levofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics; D000077266:Moxifloxacin; D009883:Ophthalmic Solutions; D011804:Quinolines / Q000008:administration & dosage / Q000493:pharmacokinetics; D011817:Rabbits; D014018:Tissue Distribution; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D001381:Azepines; D024841:Fluoroquinolones; D009883:Ophthalmic Solutions; D011804:Quinolines; D064704:Levofloxacin; C522124:besifloxacin; D000077734:Gatifloxacin; D000077266:Moxifloxacin