title: Suitability of a colorimetric method for the selective determination of chitosan in dietary supplements.
abstract: A colorimetric method previously described for the determination of chitosan has been evaluated because lack of linearity had been observed at certain concentrations. Calibration curves of varied-characteristic chitosans, recovery studies and chitosan quantification in seven commercial dietary supplements have been performed. Some analysis conditions including the solvent of the samples have been studied and optimised. Different data combinations have been checked in order to select the widest range of concentrations where no serial correlation was found. With the selected conditions the method is linear, reproducible and provides reliable results in the analysis of the chitosan content in capsules. Its selectivity has been proved by the lack of interference with other compounds present in the dietary supplements. But in the case of tablet products, the presence of cellulose and magnesium stearate may produce an underestimation of the chitosan content.
authors.affiliation: Institute of Food Science Research, CIAL (UAM-CSIC) C/ Nicolás Cabrera 9 , 28049 Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Miralles
authors.affiliation: Instituto de Estudios Biofuncionales, Dpto. Química Física II. Fac. Farmacia, Universidad Complutense de Madrid, Po Juan XXIII no. 1, 28040 Madrid, Spain.
authors.forename: Marian
authors.initials: M
authors.lastname: Mengíbar
authors.affiliation: Instituto de Estudios Biofuncionales, Dpto. Química Física II. Fac. Farmacia, Universidad Complutense de Madrid, Po Juan XXIII no. 1, 28040 Madrid, Spain.
authors.forename: Ruth
authors.initials: R
authors.lastname: Harris
authors.affiliation: Instituto de Estudios Biofuncionales, Dpto. Química Física II. Fac. Farmacia, Universidad Complutense de Madrid, Po Juan XXIII no. 1, 28040 Madrid, Spain. Electronic address: aheras@farm.ucm.es.
authors.forename: Angeles
authors.initials: A
authors.lastname: Heras
keywords: Capsule; Chitosan; Dietary supplement; Excipient; Quantitative; Tablet