HYDROGELS BASED ON CHITOSAN AND OXIDIZED CARBOXYMETHYL CELLULOSE - POTENTIAL SUPPORTS FOR DRUG IMMOBILIZATION.

The chitosan used was of medium molecular weight, with a 75% deacetylation degree. Crosslinking to obtain hydrogels was performed with partially oxidized carboxymethyl cellulose (CMC-Ox) with NaIO4, to form aldehyde groups by cleaving the C2-C3 bond and the oxidation degree of 45%. The films were obtained by cross-linking as a result of the reaction between the chitosan amine groups with CMC-Ox dialdehyde groups, working at different molar ratios -NH2/-CH=O. The amine groups amount that didn't participate at cross-linking (determined by the ninhydrin test) and the swelling degree value in different mediums decreases as the CMC-Ox amount increases as a result of cross-linking degree. The CMC-Ox and hydrogel films were characterized by SEM, FT-IR and NMR spectroscopy. CMC-Ox could constitute an appropriate cross-linking agent for chitosan having the advantage to avoid the use of another covalent cross-linker, usually toxic and the hydrogel obtained could be used as support for curcumin immobilization. [ABSTRACT FROM AUTHOR]