title: Correlation between radioactivity and chemotherapeutics of the (111)In-VNB-liposome in pharmacokinetics and biodistribution in rats.
abstract: BACKGROUND
  The combination of a radioisotope with a chemotherapeutic agent in a liposomal carrier (ie, Indium-111-labeled polyethylene glycol pegylated liposomal vinorelbine, [(111)In-VNB-liposome]) has been reported to show better therapeutic efficiency in tumor growth suppression. Nevertheless, the challenge remains as to whether this therapeutic effect is attributable to the combination of a radioisotope with chemotherapeutics. The goal of this study was to investigate the pharmacokinetics, biodistribution, and correlation of Indium-111 radioactivity and vinorelbine concentration in the (111)In-VNB-liposome.
  
  
  METHODS
  The VNB-liposome and (111)In-VNB-liposome were administered to rats. Blood, liver, and spleen tissue were collected to determine the distribution profile of the (111)In-VNB-liposome. A liquid chromatography tandem mass spectrometry system and gamma counter were used to analyze the concentration of vinorelbine and radioactivity of Indium-111.
  
  
  RESULTS
  High uptake of the (111)In-VNB-liposome in the liver and spleen demonstrated the properties of a nanosized drug delivery system. Linear regression showed a good correlation (r = 0.97) between Indium-111 radioactivity and vinorelbine concentration in the plasma of rats administered the (111)In-VNB-liposome.
  
  
  CONCLUSIONS
  A significant positive correlation between the pharmacokinetics and biodistribution of (111)Indium radioactivity and vinorelbine in blood, spleen, and liver was found following administration of the (111)In-VNB-liposome. The liposome efficiently encapsulated both vinorelbine and Indium-111, and showed a similar concentration-radioactivity time profile, indicating the correlation between chemotherapy and radiotherapy could be identical in the liposomal formulation.
authors.affiliation: Institute of Traditional Medicine, School of Medicine, National Yang- Ming University, Taipei.
authors.forename: Wen-Chuan
authors.initials: WC
authors.lastname: Lee
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Chang
authors.forename: Chih-Min
authors.initials: CM
authors.lastname: Huang
authors.forename: Yu-Tse
authors.initials: YT
authors.lastname: Wu
authors.forename: Liang-Cheng
authors.initials: LC
authors.lastname: Chen
authors.forename: Chung-Li
authors.initials: CL
authors.lastname: Ho
authors.forename: Tsui-Jung
authors.initials: TJ
authors.lastname: Chang
authors.forename: Te-Wei
authors.initials: TW
authors.lastname: Lee
authors.forename: Tung-Hu
authors.initials: TH
authors.lastname: Tsai
mesh_terms: D000818:Animals; D007205:Indium Radioisotopes / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D016014:Linear Models; D008081:Liposomes / Q000493:pharmacokinetics*; D008099:Liver / Q000737:chemistry; D008297:Male; D011849:Radioactive Tracers; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013154:Spleen / Q000737:chemistry; D014018:Tissue Distribution; D014747:Vinblastine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology; D000077235:Vinorelbine
chemical_list: D007205:Indium Radioisotopes; D008081:Liposomes; D011849:Radioactive Tracers; D014747:Vinblastine; D000077235:Vinorelbine