Comparison of the absorption and metabolism of sulphasalazine and acrylic-coated 5-amino salicylic acid in normal subjects and patients with colitis.

Serum levels of 5-amino salicylic acid ( 5ASA ) and acetyl 5ASA have been measured in volunteers after ingestion of sulphasalazine (6 g) and compared with levels after an equivalent dose of acrylic coated 5ASA (2.4 g). The serum levels of both 5ASA and acetyl 5ASA were similar after each preparation apart from an early peak of 5ASA following acrylic coated 5ASA . Serum and urinary levels for 5ASA and acetyl 5ASA have been measured in colitic patients following equivalent doses of sulphasalazine and acrylic coated 5ASA . Serum levels were similar; 25% of the calculated ingested 5ASA was excreted in the urine after sulphasalazine compared with 20% following acrylic coated 5ASA .