title: Chitosan/cellulose acetate microspheres preparation and ranitidine release in vitro.
abstract: New microspheres containing hydrophilic core and hydrophobic coating as a controlled-release system with no toxic reagents were proposed. Water in oil in water (W/O/W) emulsion and solvent evaporation methods were used to make chitosan/ cellulose acetate (CCA) microspheres sized 200 - 400 microm. Ranitidine hydrochloride, as a model drug, was investigated for its release properties in vitro. The loading efficiency and release rate of ranitidine were affected by chitosan concentration and molecular weight. Higher loadings were obtained at lower concentrations in the interval of 1% to 2%. With chitosan at a 2% concentration microspheres could be obtained with more spherical appearance, smaller size, and higher ranitidine loading efficiency microspheres than at other concentrations. Among the different molecular weight chitosan (47, 145, 308, 499, and 1130 KD) microspheres, the high molecular weight chitosan (1130 KD) microspheres had relatively high loading efficiency (10%). Molecular weight and concentration of chitosan as well as the size of microspheres affected the release of ranitidine. Microspheres smaller than 280 microm released the drug faster than did the bigger by about 10%. The optimal condition for the preparation of the microspheres was chitosan concentration 2%, molecular weight 1130 KD. The ranitidine release from the microspheres was 30% during 48 h in phosphate-buffer saline medium.
authors.affiliation: College of Marine Life Science, Ocean University of China, Qingdao, P.R. China.
authors.forename: H Y
authors.initials: HY
authors.lastname: Zhou
authors.forename: Xi Guang
authors.initials: XG
authors.lastname: Chen
authors.forename: C S
authors.initials: CS
authors.lastname: Liu
authors.forename: X H
authors.initials: XH
authors.lastname: Meng
authors.forename: L J
authors.initials: LJ
authors.lastname: Yu
authors.forename: X Y
authors.initials: XY
authors.lastname: Liu
authors.forename: N
authors.initials: N
authors.lastname: Liu
mesh_terms: D000284:Administration, Oral; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D005079:Excipients / Q000737:chemistry*; D006635:Histamine H2 Antagonists / Q000008:administration & dosage* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D011899:Ranitidine / Q000008:administration & dosage* / Q000737:chemistry; D012995:Solubility; D014783:Viscosity
chemical_list: D003692:Delayed-Action Preparations; D005079:Excipients; D006635:Histamine H2 Antagonists; C005062:acetylcellulose; D011899:Ranitidine; D002482:Cellulose; D048271:Chitosan