title: [Preparation and in vitro drug release study of long-circulating hydroxycamptothecin nanoparticles].
abstract: OBJECTIVE
  To prepare long-circulating hydroxycamptothecin nanoparticles and study its in vitro drug release characteristics.
  
  
  METHODS
  The HCPT-PEG-PCL-NPs were prepared by solvent-diffusion method using PEG-PCL block copolymer synthesized as a matrix and HCPT as an antitumor agent. Then the obtained NPs were evaluated and its in vitro drug release characteristics were investigated.
  
  
  RESULTS
  When using PEG4000-PCL2000, PEG4000-PCL1250, PEG2000-PCL2000, PEG2000-PCL1250 as the carrier material to prepare NPs, the average particle size of NPs in turn were 116.1, 110.0, 119.9, 99.1 nm; the zeta potential were -22.4, - 16. 9, -33.5, - 28.8 mV; the entrapment efficiency were 88.29%, 83.10%, 80.67%, 77.46%; and the drug loading were 2.96%, 2.56%, 2.31%, 2.14%, respectively. HCPT-PEG-PCL-NPs all showed a certain degree of sustained-release characteristics and their release mechanisms were fitted to Weibull modle, which showed that the drug release process included passive diffusion and matrix-eroded procedure.
  
  
  CONCLUSIONS
  The HCPT-PEG-PCL-NPs has high entrapment efficiency, drug loading, uniform particle size, and can retard drug release in vitro, so it provides an extensive prospect for clinical application of HCPT.
authors.affiliation: Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. xfiona224@yahoo.com.cn
authors.forename: Na
authors.initials: N
authors.lastname: Xi
authors.forename: Lian-Bing
authors.initials: LB
authors.lastname: Hou
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D019540:Area Under Curve; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics*; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers / Q000737:chemistry*; D004355:Drug Stability; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004337:Drug Carriers; D007783:Lactones; D011092:Polyethylene Glycols; D002166:Camptothecin