Gastrointestinal transit and release of mesalazine tablets in patients with inflammatory bowel disease.

Gastrointestinal transit and release of a delayed-release, enteric-coated tablet of mesalazine (Claversal) were studied in 13 patients with Crohn's disease and ulcerative colitis. The tablets disintegrated a mean of 3.2 h after leaving the stomach, resulting in drug dispersion in the distal small intestine or proximal colon. Tablet disintegration closely correlated with onset of drug absorption. Peak mean concentrations of mesalazine and its main metabolite, Ac-5-ASA, were 0.5 microgram/ml and 1.0 microgram/ml, respectively, and occurred 3 to 4 h after gastric emptying. The plasma levels correlated with scintigraph images of tablet disintegration. It is concluded that the tablets effectively deliver mesalazine to the terminal ileum and proximal colon in patients with inflammatory bowel disease.