title: Chitosan crosslinked microparticles with encapsulated polyphenols: Water sorption and release properties.
abstract: Chitosan-glutaraldehyde microparticles were produced by emulsion crosslinking method to be used as drug delivery system for polyphenols from Thymus serpyllum L. aqueous extract. The effect of preparation conditions, chitosan concentration (1.5-3% w/v), and glutaraldehyde/chitosan (GA/Ch) mass ratio (0.15-1.20) on water and polyphenols transport properties was investigated. Swelling ratio of dry particles (68-230 µm) in water ranged from 280% to 530%, depending on the formulation. The decrease in swelling was observed with increased GA/Ch mass ratio (i.e. crosslinking degree) at the same chitosan concentration, or with increased chitosan concentration at the same GA/Ch mass ratio. The increase in GA/Ch mass ratio was also manifested by increased particle compactness i.e. decreased size and reduced surface roughness. The sorption capacity for polyphenols seems to be a complex interplay of swelling behaviour and interactions chitosan-glutaraldehyde-polyphenols identified by Fourier transmission infrared analysis. An increase in crystallinity of chitosan was observed upon crosslinking with glutaraldehyde and encapsulation of polyphenols, as observed by X-ray diffraction analysis. The results obtained from release kinetics of selected polyphenolic compounds (caffeic acid, rosmarinic acid, total flavonoids, and total phenol content) showed that polyphenols were released at a lower amount (2-4 times) in water, but more rapidly (45-120 min) in comparison with the release in gastric followed by intestinal simulated fluid (SGF-SIF) (120-240 min). The experimental results of the time-dependent swelling in water and polyphenols release in both, water and SGF-SIF, were analyzed with several mathematical models. The results depicted Fickian diffusion as the water transport mechanism. In the case of polyphenols, only empirical Weibull model could be suggested for describing release kinetics.
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia.
authors.forename: Kata
authors.initials: K
authors.lastname: Trifković
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia The Academy of Criminalistic and Police Studies, Department of Forensics, Belgrade, Serbia nikolla3@tmf.bg.ac.rs.
authors.forename: Nikola
authors.initials: N
authors.lastname: Milašinović
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia.
authors.forename: Verica
authors.initials: V
authors.lastname: Djordjević
authors.affiliation: Institute for Medicinal Plants Research "Dr Josif Pančić", Department for Pharmaceutical Research and Development, Belgrade, Serbia.
authors.forename: Gordana
authors.initials: G
authors.lastname: Zdunić
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia.
authors.forename: Melina
authors.initials: M
authors.lastname: Kalagasidis Krušić
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia.
authors.forename: Zorica
authors.initials: Z
authors.lastname: Knežević-Jugović
authors.affiliation: Institute for Medicinal Plants Research "Dr Josif Pančić", Department for Pharmaceutical Research and Development, Belgrade, Serbia.
authors.forename: Katarina
authors.initials: K
authors.lastname: Šavikin
authors.affiliation: Faculty of Agriculture, University of Belgrade, Belgrade, Serbia.
authors.forename: Viktor
authors.initials: V
authors.lastname: Nedović
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia.
authors.forename: Branko
authors.initials: B
authors.lastname: Bugarski
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004058:Diffusion; D016503:Drug Delivery Systems; D065546:Drug Liberation; D005976:Glutaral / Q000737:chemistry*; D007700:Kinetics; D010316:Particle Size; D059808:Polyphenols / Q000008:administration & dosage* / Q000737:chemistry; D046930:Thymus Plant / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D003432:Cross-Linking Reagents; D059808:Polyphenols; D014867:Water; D048271:Chitosan; D005976:Glutaral
keywords: Chitosan microparticles; emulsion crosslinking method; mathematical models; polyphenols release; water sorption