Controlled Release of Salidroside Microspheres Prepared Using a Chitosan and Methylcellulose Interpenetrating Polymer Network

In this work, salidroside, a functional food agent, was incorporated into novel interpenetrating polymer network microspheres (IPN-Ms) prepared by chitosan (CS) and methylcellulose (MC) for controlled release and stabilization. IPN-Ms were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry and X-ray diffraction. The result indicated that salidroside-loaded IPN-Ms (S-IPN-Ms) are hollow and highly spherical, with a coarse pleated surface and a particle size ranging from 5 to 30 µm. Schiff base formation and the hemiacetal reaction are the primary mechanisms underlying the interpenetrating network cross-linking of IPN-Ms. In S-IPN-Ms, the CS and MC were homogeneously blended, and the salidroside was molecularly and amorphously dispersed. The encapsulation efficiency of the salidroside within the S-IPN-Ms was up to 75.64 %. In the S-IPN-M complex, the release of salidroside by S-IPN-Ms was governed by burst and sustained release, and Fickian diffusion was the primary release mechanism for the entire release process. Thus, controlled release and stabilization of salidroside were achieved through incorporation of salidroside into IPN-Ms prepared by chitosan (CS) and methylcellulose.