Drug/Small Molecule:

olsalazine

Olsalazine is an anti-inflammatory drug used in the treatment of Inflammatory Bowel Disease and Ulcerative Colitis. Olsalazine is a derivative of salicylic acid. Inactive by itself (it is a prodrug), it is converted by the bacteria in the colon to mesalamine. Mesalamine works as an anti-inflammatory agent in treating inflammatory diseases of the intestines. (source: Drug Bank)

For the treatment of Inflammatory Bowel Disease and Ulcerative Colitis. (source: Drug Bank)

Orally administered olsalazine is converted to mesalamine which is thought to be the therapeutically active agent in the treatment of ulcerative colitis. The mechanism of action of mesalamine (and sulfasalazine) is unknown, but appears to be topical rather than systemic. Mucosal production of arachidonic acid (AA) metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes (LTs) and hydroxyelcosatetraenoic acids (HETEs) is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalamine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin (PG) production in the colon. (source: Drug Bank)

Olsalazine is an anti-inflammatory drug used in the treatment of Inflammatory Bowel Disease and Ulcerative Colitis. Olsalazine reduces the bowel inflammation, diarrhea (stool frequency), rectal bleeding, and abdominal pain. Like Balsalazide, Olsalazine is believed to deliver Mesalazine, or 5-aminosalicylic acid (5-ASA), past the small intestine, directly to the large intestine, which is that active site of disease in ulcerative colitis. (source: Drug Bank)

Most (98 to 99%) of an oral dose is rapidly converted into two molecules of 5-aminosalicylic acid (5-ASA) by colonic bacteria and the low prevailing redox potential found in this environment. The conversion of olsalazine to mesalamine in the colon is similar to that of sulfasalazine, which is converted into sulfapyridine and mesalamine. Approximately 0.1% of an oral dose of olsalazine is metabolized in the liver to olsalazine-O-sulfate (olsalazine-S) (source: Drug Bank)

Olsalazine and olsalazine-S are more than 99% bound to plasma proteins. Mesalamine (5-ASA) is 74% bound to plasma proteins. (source: Drug Bank)

After oral administration, olsalazine, has limited systemic bioavailability. 98-99% of the dose is converted to mesalamine (5-ASA) in the colon, which is absorbed slowly resulting in very high local concentrations in the colon. (source: Drug Bank)

Maximum single oral doses of 5g/kg in mice and rats and 2 g/kg in dogs were not lethal. (source: Drug Bank)

c1cc(c(cc1N=Nc2ccc(c(c2)C(=O)O)O)C(=O)O)O (source: Drug Bank)