Abstract:
In this study, a novel magnetic pH-sensitive N-succinyl chitosan/alginate hydrogel bead was prepared by the single factors test design for controlled the delivery of 5- Fluorouracil (5-FU) and the bead was evaluated for pH sensitivity due to the drug release characteristics. The structure and surface morphology of the bead were characterized by FTIR, SEM, and VSM. The effects of six different factors influencing the swelling ability of the hydrogel bead were also investigated, such as the weight ratio of N-succinyl chitosan and alginate (X1), the weight ratio of drug to polymer (X2), CaCl₂ concentration (X3) ,the volume ratio of N-succinyl chitosan/alginate to CaCl₂ (X4), crosslinking time (X5), the weight ratio of Fe₃O₄ to polymer (X6). In addition, the delivery behavior of 5-FU from the hydrogel bead was studied. The amount of 5-FU released from the hydrogel bead at pH 1.5 was relatively low (47.93%), while this value approached 93.91% at pH 6.8. The results clearly suggested that the N-succinyl chitosan/alginate beads had pH-dependent swelling behaviors and a continuous release of 5-FU. From the magnetometer measurements data, the beads also had super paramagnetic property as well as fast magnetic response. So the magnetic pH-sensitive beads may be a potential polymeric carrier for drug delivery in the intestinal tract.

Keywords: 5- Fluorouracil, Magnetic/ pH-sensitivety, Hydrogel, N–succinyl chitosan, Release.