title: [Development of a novel drug dilivery system based on calcium phosphate cement with methotrexate and its drug release test in vitro].
abstract: OBJECTIVE
  To develop a novel drug dilivery system based on calcium phosphate cement (CPC) with methotrexate (MTX) as a model drug and to study its drug release in vitro.
  
  
  METHODS
  Three MTX mass fractions (0.1%, 0.2%, and 0.5%) were tested after solidification, and the compound of CPC-MTX were put into the simulated body fluid at 37 degrees C. The concentration of MTX was tested by high-performance liquid chromatography at day 2, 5, 10, 16 hours, 1, 2, 3, 5, 8, 10, 15, 20, 25, 30, 35, 40, and 45 days. The drug dilivery curves were drawn and drug dilivery rules were analyzed.
  
  
  RESULTS
  MTX was released slowly and stably from the compound of CPC-MTX. Remarked prophase of drug release was noted, which conformed with the Higuchi equation. The drug release rate and concentration was related with the concentration of MTX in compound but not with the thickness and shape of CPC. The releasing time was not affected by the concentration of MTX.
  
  
  CONCLUSIONS
  A stable drug dilivery system can be developed by loading proper concentration of MTX into CPC.
authors.affiliation: Department of Orthopaedics, Qilu Hospital of Shandong University, Jinan 250012, China. yzpyzp@163.com
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Han
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Li
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations; D007700:Kinetics; D008727:Methotrexate / Q000008:administration & dosage* / Q000032:analysis
chemical_list: D002130:Calcium Phosphates; D003692:Delayed-Action Preparations; C020243:calcium phosphate; D008727:Methotrexate