title: Preparation and characterization of novel sinomenine microcapsules for oral controlled drug delivery.
abstract: BACKGROUND
  Developing a sustained release drug to cure arthritis is needed. Sinomenine (SIN) is abstracted from sinomenium acutum and widely used in the treatment of various rheumatism and arrhythmia with few side effects. The primary aim of this study is to develop SIN microcapsules with polyelectrolyte multilayers for controlled drug release.
  
  
  METHODS
  SIN microcrystals were encapsulated with chitosan, gelatin, and alginate by layer-by-layer technique, such as (gelatin/alginate)(4) and (chitosan/alginate)(6). The size distribution, zeta-potential, stability, and morphology of the microcapsules were characterized by a particle size analyzer, zetasizer, ultraviolet spectroscopy, and transmission electron microscope, respectively. The in vitro controlled release pattern of SIN was studied using a diffusion cell assembly at physiological pH of 6.8 or 1.4.
  
  
  RESULTS
  Light stability of these microcapsules was improved after microencapsulation. Compared with release rate of the SIN microcapsules coated by the poly(dimethyldiallyl ammonium chloride)/alginate and gelatin/alginate multilayers, release rate of the SIN microcapsules coated with chitosan/alginate multilayers was fast. Release rate progressively decreased with the increase of chitosan/alginate bilayer number and the decrease of pH value of release medium.
  
  
  CONCLUSIONS
  These novel SIN microcapsules may be developed into oral controlled drug delivery for rheumatism and arthritis.
authors.affiliation: Design and Research Institute of Energy Engineering, Zhejiang University, Hangzhou, China.
authors.forename: Dengshui
authors.initials: D
authors.lastname: Shi
authors.forename: Richard
authors.initials: R
authors.lastname: Greever
authors.forename: Youfang
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000284:Administration, Oral; D000327:Adsorption; D000700:Analgesics / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics; D001682:Biological Availability; D002214:Capsules; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D004355:Drug Stability; D009019:Morphinans / Q000008:administration & dosage* / Q000032:analysis / Q000493:pharmacokinetics*; D010316:Particle Size; D013696:Temperature
chemical_list: D000700:Analgesics; D002214:Capsules; D003692:Delayed-Action Preparations; D009019:Morphinans; C009271:sinomenine