Modification of Starch by Grafting Acetylsalicylic Acid: Synthesis, Characterization, and Application in Drug Release Domain

Abstract

A series of modified starches were prepared by grafting acetylsalicylic acid (AsA) into starch by an esterification reaction then coated with poly(vinylalcohol).The structure of Starch-graft-AsA was confirmed by FTIR, NMR, and DSC. The release of AsA occurred via a retroesterification reaction of this modified coated starch (SAC) during 76 h at different pHs and AsA contents. The diffusion coefficient of AsA in the SAC matrix followed a Fickian model. The effect of AsA amount grafted on starch revealed that the higher AsA amount released was reached with SAC containing 16.18 mol% of AsA at pH 7.