RT Journal Article SR Electronic T1 Effect of polymer coating on faecal recovery of ingested 5-amino salicylic acid in patients with ulcerative colitis. JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1084 OP 1089 DO 10.1136/gut.28.9.1084 VO 28 IS 9 A1 H A Mardini A1 D C Lindsay A1 C M Deighton A1 C O Record YR 1987 UL http://gut.bmj.com/content/28/9/1084.abstract AB It has been suggested that polymer coating might retard jejunal absorption of 5-amino salicylic acid (5-ASA) and thus promote delivery to its colonic site of action. Twenty three patients with active (nine), or quiescent (14) ulcerative colitis were given either uncoated or coated 5-ASA (Asacol) 400 mg qds for one to three weeks, after which they ingested five 1.5 ml dialysis membrane sachets which were recovered from the stool in the next 72 hours. After one week of treatment the concentration of 5-ASA in the faecal dialysate, urine, and fasting plasma in those receiving the coated and uncoated preparations were respectively: 25.4 +/- 5.1 compared with 1.2 +/- 0.4 mmol/l (p less than 0.001); 0.34 +/- 0.21 compared with 0.70 +/- 0.29 mmol/24h (NS) and 11.1 +/- 4.2 compared with 0.07 +/- 0.03 mumol/l (p less than 0.02). Faecal excretion of the drug appeared to be greater in patients with active colitis than in those with quiescent disease. Thus coating with pH dependent methacrylic acid copolymer B is a very effective method of promoting delivery of 5-ASA to the colon, stool dialysate concentrations being 20 fold more than those in controls. Increased trough plasma concentrations in the polymer coating group probably reflect delayed intestinal absorption but no evidence of plasma accumulation after 21 days of therapy was found.