title: [Preparation of sustained-release nitrendipine microspheres with a solid dispersed structure in liquid system].
abstract: OBJECTIVE
  To prepare the sustained-release nitrendipine microspheres with a solid dispersed structure in liquid system.
  
  
  METHODS
  The sustained-release nitrendipine microspheres with a solid dispersed structure was prepared in liquid system by combining spherical crystallization technique and solvent deposition method in one step. The resultant microspheres were evaluated for the recovery, micromeritc properties, incorporation efficiency. The factors of effect on the formation and the release rate of microspheres were also investigated.
  
  
  RESULTS
  The recovery of microspheres (280-900 microns) was more than 70% and the bulk density was around 0.7 kg.L-1. The incorporation efficiency always exceeded 95%. The formation of microspheres was mainly affected by the amount of bridging liquid and the emulsifying agents in poor solvent. The release rate of nitrendipine from the microspheres could be controlled as desired by adjusting the ratio of talc to Eudragit RS PO in the formulation.
  
  
  CONCLUSIONS
  The presented method was suitable for preparing sustained-release microspheres of a water insoluble drug.
authors: Department of Pharmaceutics, School of Pharmaceutical Science, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors: Ming-shi
authors: MS
authors: Yang
authors: Fu-de
authors: FD
authors: Cui
authors: He
authors: H
authors: Yang
authors: Peng
authors: P
authors: Gao
authors: Peng
authors: P
authors: Yue
authors: Liang
authors: L
authors: Wang
authors: Yu-ling
authors: YL
authors: Fan
mesh_terms: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D008863:Microspheres; D009568:Nitrendipine / Q000008:administration & dosage*; D010316:Particle Size; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D009568:Nitrendipine