title: [Liberation of folic acids from composite chitosan films].
abstract: Thin films were prepared by the method of evaporation of aqueous solutions of chitosan or its mixtures with poloxamer 407, gelatin, or polyvinyl alcohol. Films of varying thickness were cross-linked with phosphate ions. They contained micronized folic acid in a concentration of 9.1% or 3.2%. Prolonged several hours' liberation of folic acid into isotonic phosphate buffer at pH 5.5, 6.0, and 6.5 was examined. In the initial stage, the mechanism of liberation was governed by diffusion of the dissolved fraction, at higher pH values a higher rate of dissolution of the substance played its role. In some composites, sorption of folic acid to chitosan in an extent dependent on the composition of composites and current acidity of the medium was demonstrated.
authors.affiliation: Katedra farmaceutické technologie Farmaceutické, biochemické fakulty Univerzity Záhreb, Záhreb, Chorvatsko.
authors.forename: A
authors.initials: A
authors.lastname: Martinac
authors.forename: T
authors.initials: T
authors.lastname: Klein
authors.forename: I
authors.initials: I
authors.lastname: Kladnícková
authors.forename: M
authors.initials: M
authors.lastname: Dittrich
mesh_terms: D001672:Biocompatible Materials; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D002627:Chemistry, Physical; D048271:Chitosan / Q000737:chemistry*; D005492:Folic Acid / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D048271:Chitosan; D005492:Folic Acid
vernacular_title: Liberace kyseliny listové z kompozitních chitosanových filmů.