Oral administration has the advantages of convenience

safety

and strong patient dependence which is an ideal route of administration. However

protein drugs are easily degraded by gastric acid and protease during oral administration resulting in low bioavailability. In this paper

a drug carrier was designed for oral administration of protein drugs

which solved the problem that protein drugs were easily inactivated in the gastrointestinal tract. Glucose oxidase nanocapsules were prepared by

in-situ

free radical polymerization on the surface of the protein using glucose oxidase as a protein drug model

and the nanocapsules were grounded into powder and encapsulated in the capsul after dried at low temperature. Hypromellose was used as a raw material to prepare hypromellose acetate succinate

which was used as an enteric coating material to coat the above-mentioned capsules to obtain enteric capsules. By simulating the environment in the gastrointestinal tract

in vitro

release experiments and activity tests were performed. The results showed that the enteric-coated capsule did not dissolve within 2h under the environment of gastric juice

and the glucose oxidase in the capsule maintained high activity. Under the environment of intestinal juice

the enteric-coated capsule was dissolved and the activity of the glucose oxidase encapsulated by the nanocapsules was significantly higher than that of free glucose oxidase. The above experimental results proved that the drug-carrying system could solve the problem that oral protein drugs were easily decomposed by gastric acid and protease in the gastrointestinal tract and became inactivated.