Catechin-loaded calcium pectinate microparticles reinforced with liposome and hydroxypropylmethylcellulose: Optimization and in vivo antioxidant activity

The preparation conditions of Ca-pectinate microparticles reinforced with liposome and hydroxypropylmethylcellulose (HPMC), including CaCl2 concentration (X1), HPMC concentration (X2), and hardening time (X3), were optimized for the sustained-release of catechin into simulated gastric and intestinal fluids using response surface methodology. The optimized values of X1, X2, and X3 were found to be 5.20%, 0.08%, and 12.63 min, respectively. The microparticles prepared according to the optimized conditions released about 50% of the entrapped catechin into simulated gastric fluid during 24-h incubation period, whereas almost complete catechin release was observed in simulated intestinal fluid after 8-h incubation. Antioxidant activity of catechin in rat plasma was more effectively maintained when the catechin-loaded microparticles were fed, compared to the case of feeding free catechin, indicating that the microparticles can protect catechin molecules in the rat model and release them in a sustained manner.