Development of microparticles for oral administration of Periplaneta americana extract to treat ulcerative colitis

Ulcerative colitis (UC) is a chronic disease, which can result the inflammation of the rectum, mucosa of the colon, and submucosa. The active component such as polypeptide in Periplaneta americana, which is one of the most common insects in the nature, can be extracted to treat UC. However, the active components in Periplaneta americana extract (PAE) can be degraded in the stomach due to its extreme acidic environment and enzyme. In this study, we developed a pH-dependent drug delivery method using polymer cellulose acetate (Eudragit S100) as a carrier to deliver high concentration PAE to inflamed colon. Both in vitro and in vivo results showed the PAE-Eudragit-S100 could treat UC through delivering active drug components to colon without degradation. Eudragit S100 polymer solution was mixed with PAE ethanol solution by sonicating. Then mixture was then mixed with lecithin and glycerol monooleate in a blender . The emulsion was stirred at room temperature with a magnetic stir bar at 420 rpm. Them the microparticles were freeze-dried in a freeze-dryer. Finally, When mice were treated with this drugs. the drugs were not decomposed in stomach and small intestine but damaged in the colon, which had a good curative effeet on colitis.