Modification of Octenyl Succinic Anhydride Starch by Grafting Folic Acid and its Potential as an Oral Colonic Delivery Carrier

Abstract In this study, an oral colonic delivery system is designed using octenyl succinic anhydride (OSA) starch grafted with folic acid (FA). OSA starch with different degrees of substitution (DS) (0.011, 0.027, and 0.039) is prepared by reacting OSA with waxy maize starch. To optimize the drug‐loading efficiency, the study choses OSA6 starch (DS = 0.027) as the substrate to prepare OSA starch grafted with FA (FA‐OSA6). Fourier transform infrared spectrum confirms the successful introduction of FA. The scanning electron micrograph indicates that the surface of the FA‐OSA starch granules is rough and uneven. Drug loading analysis shows that FA‐OSA6 starch efficiently loaded doxorubicin hydrochloride (DOX) up to 87.71%. In vitro release studies suggest that the drug‐loaded complex released only 15.8% DOX through the upper gastrointestinal tract. The cell viability assay shows that the drug‐loaded complex effectively inhibits the growth of colon cancer cells (Caco‐2). These results suggest that OSA6 starch grafted with FA has potential as an oral colonic delivery carrier for DOX.