title: Pharmacokinetics of intravitreal bevacizumab (Avastin®) in rabbits.
abstract: OBJECTIVE
  To describe the pharmacokinetics of intravitreal bevacizumab (Avastin®) in rabbits.
  
  
  METHODS
  The right eye of 20 rabbits was injected intravitreally with 1.25 mg/0.05 mL bevacizumab. Both eyes of four rabbits each time were enucleated at days 1, 3, 8, 15, and 29. Bevacizumab concentrations were measured in serum, aqueous humor, and vitreous.
  
  
  RESULTS
  Maximum vitreous (406.25 μg/mL) and aqueous humor (5.83 μg/mL) concentrations of bevacizumab in the right eye were measured at day 1. Serum bevacizumab concentration peaked at day 8 (0.413 μg/mL) and declined to 0.032 μg/mL at 4 weeks. Half-life values in right vitreous, right aqueous humor, and serum were 6.61, 6.51, and 5.87 days, respectively. Concentration of bevacizumab in the vitreous of the noninjected eye peaked at day 8 (0.335 ng/mL) and declined to 0.218 ng/mL at 4 weeks. In the aqueous humor of the noninjected eye, maximum concentration of bevacizumab was achieved at day 8 (1.6125 ng/mL) and declined (to 0.11 ng/mL) at 4 weeks.
  
  
  CONCLUSIONS
  The vitreous half-life of 1.25 mg/0.05 mL intravitreal bevacizumab was 6.61 days in this rabbit model. Maximum concentrations of bevacizumab were reached at day 1 in both vitreous and aqueous humor of the right eye and at day 8 in the serum. Very low concentrations of bevacizumab were measured in the fellow noninjected eye.
authors.affiliation: Laboratory for Experimental Surgery and Surgical Research 'N.S.Christeas', School of Medicine, National and Kapodistrian University of Athens, 15b AgiouThoma Street, 11527, Athens, Greece. csinapis@yahoo.gr
authors.forename: Christos I
authors.initials: CI
authors.lastname: Sinapis
authors.forename: John G
authors.initials: JG
authors.lastname: Routsias
authors.forename: Angelos I
authors.initials: AI
authors.lastname: Sinapis
authors.forename: Dimitrios I
authors.initials: DI
authors.lastname: Sinapis
authors.forename: George D
authors.initials: GD
authors.lastname: Agrogiannis
authors.forename: Alkistis
authors.initials: A
authors.lastname: Pantopoulou
authors.forename: Stamatis E
authors.initials: SE
authors.lastname: Theocharis
authors.forename: Stefanos
authors.initials: S
authors.lastname: Baltatzis
authors.forename: Efstratios
authors.initials: E
authors.lastname: Patsouris
authors.forename: Despoina
authors.initials: D
authors.lastname: Perrea