title: pH-dependent release property of alginate beads containing calcium carbonate particles.
abstract: Alginate bead containing calcium carbonate particle were prepared by dropping the suspension of alginate/calcium carbonate (4/1, w/w) into aqueous solution of CaCl(2) (0.1 M). The pH-dependent release property of the bead was observed for 12 h using blue dextran as a model drug. The release increased up to 4 h in a saturation manner. When no calcium carbonate was contained, the release exhibited no marked variation with pH and the values were 27-39%. On the other hand, in case calcium carbonate was included in the matrix of alginate beads, intensive release(40-50%) was achieved in acidic and neutral conditions and the degrees of release were suppressed in alkali conditions and the values were approximately 20%. The pH-sensitive release property is possibly because the particles of calcium carbonate embedded in the matrix of beads were leached out in acidic and neutral conditions, leaving cavities in the matrix. The cavities are likely to be main pathways for the release of blue dextran.
authors.affiliation: College of Bioscience & Biotechnology and Research Institute of Bioscience and Biotechnology, Kangwon National University, Chunchon, Kangwon-do, Korea.
authors.forename: M R
authors.initials: MR
authors.lastname: Han
authors.forename: M C
authors.initials: MC
authors.lastname: Kwon
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
authors.forename: J C
authors.initials: JC
authors.lastname: Kim
authors.forename: J D
authors.initials: JD
authors.lastname: Kim
authors.forename: S K
authors.initials: SK
authors.lastname: Yoo
authors.forename: I S
authors.initials: IS
authors.lastname: Sin
authors.forename: S M
authors.initials: SM
authors.lastname: Kim
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D003911:Dextrans / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D016062:Porosity
chemical_list: D000464:Alginates; D003692:Delayed-Action Preparations; D003911:Dextrans; D006603:Hexuronic Acids; D020723:Glucuronic Acid; C017080:blue dextran; D002119:Calcium Carbonate