title: Aqueous starch acetate dispersion as a novel coating material for controlled release products.
abstract: The aim of this study was to evaluate film-formation properties of a novel, organic solvent-free aqueous dispersion of potato starch acetate (SA; degree of substitution 2.8) and its ability to control drug release from a coated tablet. Initially, film-formation mechanisms and drug permeabilities of both organic solvent and dispersion-based SA free films (prepared by cast or spraying techniques) were investigated. The SA dispersion was suitable for the fluid-bed coating process, forming strong films with complete coalescent polymeric spheres. The model compounds predominantly permeated via the micro-pores of SA free films, which resulted from the leaching of water-soluble excipients from the dispersion. Thus, the permeation rate depended on the film structure rather than the physico-chemical properties of the penetrant. In the case of SA-coated tablet, drug release was sustained when the coating level was increased (from 12% to 20%, stated as a weight gain), and also as lipophilicity of the drug increased. When compared to the reference polymer dispersion (Surelease), SA coatings showed better mechanical properties against the osmotic pressure caused by a hydrophilic core tablet. These results clearly demonstrate that SA dispersion has high utility as a novel aqueous coating material for controlled release products.
authors.affiliation: Department of Pharmaceutics, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland. Maarit.Tarvainen@uku.fi
authors.forename: Maarit
authors.initials: M
authors.lastname: Tarvainen
authors.forename: Soili
authors.initials: S
authors.lastname: Peltonen
authors.forename: Hannu
authors.initials: H
authors.lastname: Mikkonen
authors.forename: Minna
authors.initials: M
authors.lastname: Elovaara
authors.forename: Minna
authors.initials: M
authors.lastname: Tuunainen
authors.forename: Petteri
authors.initials: P
authors.lastname: Paronen
authors.forename: Jarkko
authors.initials: J
authors.lastname: Ketolainen
authors.forename: Riitta
authors.initials: R
authors.lastname: Sutinen
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations / Q000737:chemistry* / Q000493:pharmacokinetics; D013213:Starch / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000493:pharmacokinetics; D014867:Water / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D014867:Water; D013213:Starch; C050766:starch acetate