Preparation, Characterization and Drug Release of Chitosan Hydrogels Derived From Substituted Salicylaldehyde

Abstract

Chitosan-based hydrogels (CSAD1, CSAD2 and CSAD3) have been successfully prepared by dynamic imine reaction between chitosan and varying ratios of 2-[(2,3-dihydroxy)-1propoxy]benzaldehyde (SAD) as a linker group respectively. SAD was synthesized from salicylaldehyde and glycidol by atom economy method. FT-IR and NMR data were used to determine the SAD and hydrogels' structures. The fabricated hydrogels exhibit a porous structure that the pore size decreased with increasing ratio of SAD group. Hydrogels were swelled in aqueous media but not soluble in both acidic and alkaline medium. The highest swelling capacity was obtained at pH 7 with the order of CSAD1, CSAD2, and CSAD3, respectively. The high thermal behavior of the hydrogels was tested by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Ibuprofen was selected as a model drug for the drug release behaviors of the hydrogels. Release of ibuprofen is influenced by the pore sizes of the hydrogels in order of CSAD1, CSAD2, and CSAD3, respectively.