title: A new vitreal drug delivery system using an implantable biodegradable polymeric device.
abstract: OBJECTIVE
  The authors evaluated the feasibility of using an implantable biodegradable polymeric device to deliver drugs into the vitreous humor.
  
  
  METHODS
  Two types of devices were prepared by compression-molding polymers of poly(DL-lactic acid) of two different molecular weights. The molecular weights of the poly(DL-lactic acid) used were 5,600 (device-1) and 9,100 (device-2). Sodium fluorescein (NaF) served as a hydrophilic drug marker. The release of the dye from the devices was studied in vitro. The intravitreal kinetics of NaF was evaluated in rabbits in vivo by fluorophotometry. The eyes were evaluated electrophysiologically and histologically to determine if there were toxic effects.
  
  
  RESULTS
  Device-1 and device-2 released NaF for more than 25 and 45 days, respectively, in vitro. Detectable concentrations of NaF were present in the vitreous up to 17 days (device-1) and 28 days (device-2). Both types of devices were well tolerated, with no noted toxic effects.
  
  
  CONCLUSIONS
  These results suggested that this device may be a potentially effective system to deliver drugs in the vitreous.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Kyoto University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kimura
authors.forename: Y
authors.initials: Y
authors.lastname: Ogura
authors.forename: M
authors.initials: M
authors.lastname: Hashizoe
authors.forename: H
authors.initials: H
authors.lastname: Nishiwaki
authors.forename: Y
authors.initials: Y
authors.lastname: Honda
authors.forename: Y
authors.initials: Y
authors.lastname: Ikada
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001673:Biodegradation, Environmental; D003228:Conjunctiva / Q000473:pathology; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D004343:Drug Implants; D005240:Feasibility Studies; D019793:Fluorescein; D005452:Fluoresceins / Q000493:pharmacokinetics; D007773:Lactates; D019344:Lactic Acid; D008970:Molecular Weight; D011091:Polyesters; D011108:Polymers; D011817:Rabbits; D012590:Sclera / Q000473:pathology; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D004343:Drug Implants; D005452:Fluoresceins; D007773:Lactates; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D019793:Fluorescein