title: Influence of lactose addition to gentamicin-loaded acrylic bone cement on the kinetics of release of the antibiotic and the cement properties.
abstract: The purpose of this study was to characterize a poly(methyl methacrylate) bone cement that was loaded with the antibiotic gentamicin sulphate (GS) and lactose, which served to modulate the release of GS from cement specimens. The release of GS when the cement specimens were immersed in phosphate-buffered saline at 37 degrees Celsius was determined spectrophotometrically. The microstructure, porosity, density, tensile properties and flexural properties of the cements were determined before and after release of GS. A kinetics model of the release of GS from the cement that involved a coupled mechanism based on dissolution/diffusion processes and an initial burst effect was proposed. Dissolution assay results showed that drug elution was controlled by a diffusion mechanism which can be modulated by lactose addition. Density values and mechanical properties (tensile strength, flexural strength, elastic modulus and fracture toughness) were reduced by the increased porosity resulting from lactose addition, but maintained acceptable values for the structural functions of bone cement. The present results suggest that lactose-modified, gentamicin-loaded acrylic bone cements are potential candidates for use in various orthopaedic and dental applications.
authors.affiliation: Departamento de Estadistica e Investigación Operativa, Universidad Complutense de Madrid, Facultad de Farmacia, E28040 Madrid, Spain. gloriafr@mat.ucm.es
authors.forename: Gloria
authors.initials: G
authors.lastname: Frutos
authors.forename: José Ygnacio
authors.initials: JY
authors.lastname: Pastor
authors.forename: Noelia
authors.initials: N
authors.lastname: Martínez
authors.forename: María Rosa
authors.initials: MR
authors.lastname: Virto
authors.forename: Susana
authors.initials: S
authors.lastname: Torrado
mesh_terms: D000042:Absorption; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000737:chemistry; D001843:Bone Cements / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D055119:Elastic Modulus; D005839:Gentamicins / Q000008:administration & dosage / Q000737:chemistry*; D006244:Hardness; D007700:Kinetics; D007785:Lactose / Q000737:chemistry*; D008422:Materials Testing; D019904:Polymethyl Methacrylate / Q000008:administration & dosage / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D001843:Bone Cements; D004337:Drug Carriers; D005839:Gentamicins; C035124:CMW cement; D019904:Polymethyl Methacrylate; D007785:Lactose