Preparation and characterization of vanillin-chitosan Schiff base zinc complex for a novel Zn sustained released system.

In this work, a novel sustained released system (VCSB-Zn(II)) for zinc supplements was built by vanillin-chitosan Schiff base (VCSB) chelated with Zn to improve the zinc trace element utilization ratio. Samples were characterized by FT-IR, H NMR, XRD, SEM, and TGA. The results showed that VCSB exhibited a more excellent chelation capacity of Zn than chitosan. The chelation capacity of VCSB was about 1.7 times more than that of chitosan, corresponding to 50.96 mg/g and 29.91 mg/g, respectively. Furthermore, VCSB-Zn(II) showed excellent sustained released performance at simulated gastric fluid because of the acid slow-dissolving ability. And the higher the CN content of VCSB, the higher the cumulative release rate (R) of Zn, the highest R reached 77.81%. The sustained released curves were described by the first-order and Korsmeyer-Peppas equation, which described the Zn sustained released performance caused by the dissolution of VCSB-Zn(II) and Fick diffusion. This Zn sustained released system shows great potential in the application in the field of trace elements supplements for animals.