title: Impregnation and release of aspirin from chitosan/poly(acrylic acid) graft copolymer microspheres.
abstract: The purpose of this study was to produce aspirin-impregnated microspheres of chitosan/poly(acrylic acid) copolymer in order to evaluate the release characteristics as a function of pH, simulating the fluids in the gastrointestinal tract. Chitosan microspheres were obtained by the coacervation-phase separation method, induced by the addition of a non-solvent (NaOH 2.0 M solution). The microspheres were cross-linked with glutaraldehyde, reduced with sodium cianoborohydride and grafted with poly(acrylic acid). The impregnation of aspirin into chitosan/poly(acrylic acid) copolymer microspheres was achieved by the dissolution of the drug in water:ethanol (2:1), which was adsorbed by the microspheres for 24h at 25 degrees C. The efficiency of aspirin impregnation was high (approximately 94%). The approach employed herein in the production of aspirin-impregnated microspheres using chitosan/poly(acrylic acid) can be a suitable drug-release control system.
authors.affiliation: Departamento de Química, Universidade Estadual de Ponta Grossa, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Nascimento
authors.forename: M C
authors.initials: MC
authors.lastname: Laranjeira
authors.forename: V T
authors.initials: VT
authors.lastname: Fávere
authors.forename: A
authors.initials: A
authors.lastname: Josué
mesh_terms: D000180:Acrylic Resins / Q000008:administration & dosage*; D001241:Aspirin / Q000008:administration & dosage*; D002686:Chitin / Q000008:administration & dosage* / Q000031:analogs & derivatives; D048271:Chitosan; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D008863:Microspheres
chemical_list: D000180:Acrylic Resins; D002686:Chitin; C006903:carbopol 940; D048271:Chitosan; D001241:Aspirin