title: In vivo and in vitro release of macromolecules from polymeric drug delivery systems.
abstract: In vivo release rates of a macromolecule from an ethylene-vinyl acetate copolymer have been shown to be indistinguishable from those of identical implants tested in vitro. The studies were conducted for approximately 2 months, and two different techniques were used to assess release rates. One of these techniques, using [3H]inulin as a marker, may be particularly useful in future studies assessing in vivo release rates from drug delivery systems. The appearance of [3H]inulin in the urine of rats bearing implants allowed continuous monitoring of release. A histological evaluation of tissue sections surrounding polymer implanted for 7 months showed no inflammatory cell reaction.
mesh_terms: D003692:Delayed-Action Preparations; D004343:Drug Implants; D007444:Inulin; D007700:Kinetics; D046911:Macromolecular Substances; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D011108:Polymers; D011145:Polyvinyls
chemical_list: D003692:Delayed-Action Preparations; D004343:Drug Implants; D046911:Macromolecular Substances; D004364:Pharmaceutical Preparations; D011108:Polymers; D011145:Polyvinyls; C016438:ethylenevinylacetate copolymer; D007444:Inulin