Filmes de amido reticulado: estudo da incorporação e liberação de sulfato de condroitina

Cassava starch films and cassava starch / chondroitin sulfate films cross-linked with citric acid (AC) were prepared by the casting technique and produced from a solution of starch and of SC using glycerol as a plasticizer. The effect of the concentration of the AC and the proportion of chondroitin sulfate (SC) on the thermal properties (TGA), water vapor permeability (PVA) and the release kinetics of SC were evaluated. FTIR analysis indicate the presence of ester bond formation between the starch and citric acid chains, confirming the crosslinking reaction. The thermal stability of the films increased with the addition of AC and decreased with the addition of SC. Both the AC and the SC had the effect of increasing the PVA of the films. The SC release presented anomalous transport mechanism with 1 >n> 0.5 (Korsmeyer-Peppas equation) for all films and the release rate (k) dependent on the quantities of AC and SC.