Is 5-Aminosalicylic Acid Delivered Directly to the Colon by Olsalazine?

Abstract

The aims of this investigation were to determine the amount of olsalazine which is delivered to the colon and the amount biotransformed to 5-ASA and N-acetyl-5-ASA, and to study the effect of concomitant food intake on the availability of 5-ASA and acetyl-5-ASA after olsalazine, 1 g. Studies in 10 subjects who received a single 1 g oral dose showed that olsalazine is transported intact to the colon and that less than 3% is absorbed. Olsalazine is, therefore, biologically transformed to 5-ASA and acetyl-5-ASA in the large intestine. The small amount of olsalazine absorbed has a short β half-life of 56 minutes. The simultaneous intake of food in a study involving eight healthy volunteers slightly diminished the low absorption of olsalazine, though the effect was not significant, and no effect was seen on the absorption of 5-ASA.

Key Words:

• Acetyl-5-ASA
• 5-ASA
• colon delivery
• olsalazine