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Updated: Jul 19, 2026

A Freeze-Thawing Method to Prepare Chitosan-Poly(vinyl alcohol) Hydrogels Without Crosslinking Agents and Diflunisal Release Studies
Published on: January 14, 2020
Effect of ionic crosslinking on the drug release properties of chitosan diacetate matrices
Khaled M Aiedeh1, Mutasem O Taha, Yusuf Al-Hiari
1Faculty of Pharmacy, University of Jordan, Queen Rania St., Amman 11942, Jordan. Aiedeh@ju.edu.jo
Abstract:
Chitosan diacetate (CDA) was prepared by alkylating the amino moieties of chitosan with mono-iodoacetic acid. Subsequently, CDA was cross-linked with Al3+, Zn2+, and Ca2+ ions to yield three ionotropically crosslinked polymeric matrices. These composite matrices were characterized employing infrared spectroscopy (IR) and differential scanning calorimetry (DSC). Subsequently, they were loaded with caffeine, as a model drug, and were assessed as sustained release carriers by evaluating their caffeine release profiles. Interestingly, only CDA-Zn2+ complex sustained the release of caffeine effectively in a zero-order manner. The drug release and thermal behavior of the tested matrices agree with the relative strength of the ionic or coordination character of the bonds. This, in turn, depends on the position of the complexing ions on the electrophilic softness/hardness scale.
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