Abstract:
The aim of the present study was to prepare magnetic/pH sensitive alginate-chitosan beads loaded with the water-soluble traditional Chinese medicine Sophora alopecuroides L. total alkaloids by the ionic gelation method. Beads formulations based on the electrostatic interactions between alginate and chitosan were prepared via single factor design experiments, which were employed to investigate the combined effect of seven formulation variables, i.e., % of alginate, Fe₃O₄ nanoparticles to polymer, CaCl₂ and chitosan and the volume ratio of alginate to CaCl₂ and the crosslinking time and the polymer to drug on beads encapsulation efficiency and loading efficiency, considered as the responses to be optimized. Then, we characterized the optimal beads using SEM, FTIRS, XRD, and VSM, respectively, and investigated the influence of the swelling characteristic on the multifactorial relationships among formulation parameters. Furthermore, the delivery behavior of SATA from the optimal dry beads was evaluated in vitro. We found that the beads exhibited good pH-sensitive swelling, magnetic-response and controlled release properties due to their electrostatic interaction. The results together demonstrated that the beads can realize the goal of magnetic-target and have the potential to be used as a vehicle of SATA in the gastrointestinal administration.

Keywords: Sophora alopecuroides L., Total Alkaloids, Magnetic/pH Sensitivity, Hydrogel Beads, Swelling Characteristic, Delivery Property.