Bioavailability of single and multiple doses of enteric-coated mesalamine and sulphasalazine.
The bioavailibity of mesalamine from enteric-coated mesalamine and sulphasalazine was determined following a single dose and at steady state in healthy subjects in crossover studies. Plasma concentrations and urinary excretion of mesalamine and its major metabolite, N-acetyl-5-aminosalicylic acid, were measured. After a single dose of enteric-coated mesalamine, about 10 h elapsed before the onset of measurable plasma drug concentrations, probably representing gastro-intestinal transit prior to drug release near the ileocaecal junction. The elimination kinetics were similar for a single oral dose and steady state using enteric-coated mesalamine, but after both single and multiple administration of enteric-coated mesalamine only about 20% of the mesalamine given was absorbed, with about 80% estimated to remain for colon therapeutic activity. It is concluded that, despite different mechanisms of mesalamine release, enteric-coated mesalamine and sulphasalazine produced similar mesalamine absorption.
Corey
A E
AE
Biopharmaceutics Section, Norwich Eaton Pharmaceuticals, Inc., New York 13815.
Rose
G M
GM
Conklin
J D
JD
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000636:Aminosalicylic Acids / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D004334:Drug Administration Schedule; D006801:Humans; D008297:Male; D019804:Mesalamine; D012460:Sulfasalazine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013608:Tablets, Enteric-Coated
D000636:Aminosalicylic Acids; D013608:Tablets, Enteric-Coated; D012460:Sulfasalazine; D019804:Mesalamine; C028836:N-acetyl-5-aminosalicylic acid