[Ulcerative colitis--colon delivery of 5-aminosalicylic acid]

Ulcerative colitis, Crohn's disease and hemorrhage colitis are typical example of colon specific diseases. The targeting of the drugs for these colon specific diseases was attempted by a new technology, where ethylcellulose (EC) was used as pharmaceutical material. Especially, pressure-controlled colon delivery capsule (PCDC) made of EC is a unique system. PCDC was prepared by coating the inner surface of gelatin capsule with water-insoluble polymer, EC. By adjusting the coating thickness of EC membrane to be approximately 40 microns, colon delivery of dug were obtained both in beagle dogs and human volunteers. PCDC containing 5-ASA was prepared and was administered orally to beagle dogs. After administration, 5-ASA appeared into the systemic circulation at 3-5 h which corresponds to the colon arrival time confirmed with sulfasalazine.