The invention provides a colon-targeted gel
microsphere with a controllable core-shell ratio, and preparation and application of the colon-targeted gel
microsphere. The gel
microsphere comprises a core layer, an inner shell layer and an outer shell layer from inside to outside in sequence, wherein the core layer comprises cereal
prolamin and an
active matter; the inner shell layer comprises gel
polysaccharide; the outer shell layer comprises
chitosan, a cross-linking agent and a suspending aid. The inner shell layer and the core layer form core-shell structure
fog drops through a coaxial electrostatic spraying technology, in an outer shell layer solution, the inner shell layer gel
polysaccharide of the core-shell structure
fog drops is cross-linked with the cross-linking agent and is subjected to electrostatic layer-by-layer adsorption with
chitosan, and therefore, the colon-targeted gel microsphere is prepared. The particle size of the gel microsphere is 100-600 [mu] m, the core-shell ratio is 0.5-0.9, the encapsulation efficiency of a water-soluble
active matter is as high as 60%, the encapsulation efficiency of an
alcohol-soluble
active matter is as high as 90%, the release amounts in a
stomach simulation liquid and a
small intestine simulation liquid within 1 h and 3 h can be as low as 10% and 25%, and the gel microsphere can be efficiently delivered and targeted to the colon.