title: Influence of ethanol on aspirin release from hypromellose matrices.
abstract: Release profiles of aspirin from hypromellose matrices in hydro-ethanolic media were studied. Percent aspirin released increased with increasing levels of ethanol in the dissolution media, correlating with the drug's solubility, however, dose dumping of aspirin did not occur. An initial rapid release was observed in media comprising 40% ethanol. Release in these conditions was considered to be both erosion and diffusion-mediated, in contrast to the release in 0, 10, 20 and 30% ethanol media, where erosion-controlled release dominated. Image analysis of matrix swelling indicated a slower initial interaction between ethanol and hypromellose accounting for the initial rapid release. Cloud point studies suggested that ethanol retarded hydration of the polymer.
authors.affiliation: School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom St. L3 3AF, UK. M.Roberts1@ljmu.ac.uk
authors.forename: Matthew
authors.initials: M
authors.lastname: Roberts
authors.forename: Marco
authors.initials: M
authors.lastname: Cespi
authors.forename: James L
authors.initials: JL
authors.lastname: Ford
authors.forename: A Mark
authors.initials: AM
authors.lastname: Dyas
authors.forename: James
authors.initials: J
authors.lastname: Downing
authors.forename: Luigi G
authors.initials: LG
authors.lastname: Martini
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Crowley
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D001241:Aspirin / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004058:Diffusion; D000431:Ethanol / Q000737:chemistry*; D065347:Hypromellose Derivatives; D007700:Kinetics; D016014:Linear Models; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D008956:Models, Chemical; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013607:Tablets; D013696:Temperature; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D003692:Delayed-Action Preparations; D012997:Solvents; D013607:Tablets; D014867:Water; D000431:Ethanol; D065347:Hypromellose Derivatives; D008747:Methylcellulose; D001241:Aspirin