title: Controlled release of cyclosporine from VP-HEMA copolymer systems of adjustable resorption monitorized by MEKC.
abstract: Soluble, uncrosslinked and high molecular weight copolymers of vinylpyrrolidone, VP, with 2-hydroxyethyl methacrylate, HEMA, prepared by free radical copolymerization, are proposed as supports for the modulated release of drugs, taking cyclosporine as a model system. The copolymerization parameters described as reactivity ratios, rVP = 0.08 and rHEMA = 7.97, indicate that the copolymer systems prepared at high conversion have two main components with a microstructural arrangement which depends on the average composition, i.e., an initial HEMA-rich copolymer and a final PVP homopolymer or VP-rich copolymer. This microstructural distribution controls the resorption rate of the polymeric support and therefore the release process of cyclosporine which is demonstrated experimentally by the application of a modern technique known as micellar electrokinetic capillary chromatography (MEKC).
authors.affiliation: Instituto de Ciencia y Tecnología de Polímeros, CSIC, Madrid, Spain. ictgr23@fresno.csic.es
authors.forename: A
authors.initials: A
authors.lastname: Gallardo
authors.forename: F
authors.initials: F
authors.lastname: Fernández
authors.forename: P
authors.initials: P
authors.lastname: Bermejo
authors.forename: M
authors.initials: M
authors.lastname: Rebuelta
authors.forename: A
authors.initials: A
authors.lastname: Cifuentes
authors.forename: J C
authors.initials: JC
authors.lastname: Diez-Masa
authors.forename: J
authors.initials: J
authors.lastname: San Román
mesh_terms: D020374:Chromatography, Micellar Electrokinetic Capillary; D016572:Cyclosporine / Q000493:pharmacokinetics*; D004337:Drug Carriers; D008689:Methacrylates / Q000737:chemistry*; D011108:Polymers; D011760:Pyrrolidinones / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D008689:Methacrylates; D011108:Polymers; D011760:Pyrrolidinones; C005044:hydroxyethyl methacrylate; D016572:Cyclosporine