title: [Release mechanism of huperzine-A swelling sustained-release tablets].
abstract: OBJECTIVE
  To study the release mechanism of Huperzine-A swelling sustained-release tablets (HA-ST) and the factors influencing the release rate.
  
  
  METHODS
  The HA-ST were prepared by using Polyoxyethylene (PEO) as the matrix material, polyvinyl alcohol (PVA) as the expandable reagent and microcrystalline cellulose (MCC) as the filling reagent. The effect of the amount of PEO, PVA and MCC on the drug release from the tablets was evaluated using the release index n value of the Ritger-Peppas equation.
  
  
  RESULTS
  The addition of PEO and PVA speeded up the rate of drug release from the tablets, while MCC did not affect the release rate. The release profiles of HA-ST conformed to the Higuchi model and the release mechanism was non-Fick release that coupled diffusion and erosion.
  
  
  CONCLUSIONS
  The release of HA-ST is influenced by the amount of PEO and PVA but not the MCC. The release process can be depicted by the Ritger-Peppas equation and release mechanism was is non-Fick release.
authors.affiliation: State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Shenzhen 518507, China. tangyu44@sina.com
authors.forename: Yu
authors.initials: Y
authors.lastname: Tang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Fuyuan
authors.initials: F
authors.lastname: He
authors.forename: Cha
authors.initials: C
authors.lastname: Liu
authors.forename: Dajian
authors.initials: D
authors.lastname: Yang
mesh_terms: D000470:Alkaloids; D002482:Cellulose / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry / Q000493:pharmacokinetics*; D004058:Diffusion; D008954:Models, Biological; D011092:Polyethylene Glycols / Q000737:chemistry; D012717:Sesquiterpenes / Q000737:chemistry / Q000493:pharmacokinetics*; D013607:Tablets / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D000470:Alkaloids; D003692:Delayed-Action Preparations; D012717:Sesquiterpenes; D013607:Tablets; C050426:huperzine A; D011092:Polyethylene Glycols; D002482:Cellulose; C109691:microcrystalline cellulose