title: Preparation and characterization of ibuprofen microspheres.
abstract: Ibuprofen was microencapsulated with Eudragit RS using an o/w emulsion solvent evaporation technique. The effects of three formulation variables including the drug:polymer ratio, emulsifier (polyvinyl alcohol) concentration and organic solvent (chloroform) volume on the entrapment efficiency and microspheres size distribution were examined. The drug release rate from prepared microspheres and the release kinetics were also studied. The results demonstrated that microspheres with good range of particle size can be prepared, depending on the formulation components. The drug:polymer ratio had a considerable effect on the entrapment efficiency. However, particle size distribution of microspheres was more dependent on the volume of chloroform and polyvinyl alcohol concentration rather than the drug:polymer ratio. The drug release pattern showed a burst effect for all prepared microspheres due to the presence of uncovered drug crystals on the surface. It was shown that the release profiles of all formulations showed good correlation with the Higuchi model of release.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shaheed Beheshti University of Medical Sciences and Health Services, Tehran, Iran. nbolourtchian@yahoo.com
authors.forename: N
authors.initials: N
authors.lastname: Bolourtchian
authors.forename: K
authors.initials: K
authors.lastname: Karimi
authors.forename: R
authors.initials: R
authors.lastname: Aboofazeli
mesh_terms: D000180:Acrylic Resins; D018712:Analgesics, Non-Narcotic; D002725:Chloroform; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods; D045703:Emulsifying Agents; D007052:Ibuprofen; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008863:Microspheres; D010316:Particle Size; D011142:Polyvinyl Alcohol; D012997:Solvents; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D018712:Analgesics, Non-Narcotic; D003692:Delayed-Action Preparations; D045703:Emulsifying Agents; D012997:Solvents; C050528:Eudragit RS; D002725:Chloroform; D011142:Polyvinyl Alcohol; D007052:Ibuprofen