title: Eudragit nanoparticles containing genistein: formulation, development, and bioavailability assessment.
abstract: BACKGROUND
  Genistein, one of the major isoflavones, has received great attention as a phytoestrogen and potential cancer chemoprevention agent. However, the dissolution and bioavailability of genistein from solid oral preparations is low due to its poor water solubility.
  
  
  METHODS
  In order to improve the oral bioavailability of genistein, genistein nanoparticles were prepared by the nanoprecipitation technique using Eudragit(®) E100 as carriers and an optimized formulation of mass ratio (genistein:Eudragit E100, 1:10). The mean particle size of genistein nanoparticles was approximately 120 nm when diluted 100 times with distilled water. The drug-loaded nanoparticles were spherical on observation by transmission electric microscopy.
  
  
  RESULTS
  Encapsulation efficiency and drug loading of the genistein nanoparticles were approximately 50.61% and 5.02%, respectively. Release of drug from the genistein nanoparticles was two times greater than that from the conventional capsules. After administration of genistein suspension or genistein nanoparticles at a single dose of 100 mg/kg to fasted rats, the relative bioavailability of genistein from the nanoparticles compared with the reference suspension was 241.8%.
  
  
  CONCLUSIONS
  These results suggested that a nanoparticle system is a potentially promising formulation for the efficient delivery of poorly water-soluble drugs by oral administration.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Harbin Medical University, Harbin, China.
authors.forename: Jingling
authors.initials: J
authors.lastname: Tang
authors.forename: Na
authors.initials: N
authors.lastname: Xu
authors.forename: Hongyu
authors.initials: H
authors.lastname: Ji
authors.forename: Hongmei
authors.initials: H
authors.lastname: Liu
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Wang
authors.forename: Linhua
authors.initials: L
authors.lastname: Wu
mesh_terms: D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers / Q000737:chemistry* / Q000493:pharmacokinetics*; D019833:Genistein / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D008297:Male; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011109:Polymethacrylic Acids / Q000737:chemistry*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013535:Suspensions / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D004337:Drug Carriers; D011109:Polymethacrylic Acids; D013535:Suspensions; C038300:methylmethacrylate-methacrylic acid copolymer; D019833:Genistein
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