Gastrointestinal spread of oral prolonged-release mesalazine microgranules (Pentasa) dosed as either tablets or sachet

BACKGROUND: There is increasing interest in using higher dosages of mesalazine for the treatment of inflammatory bowel disease; however, with current mesalazine products this involves the use of 8-16 tablets per day. AIM: To evaluate the disposition, dispersion and movements of Pentasa prolonged-release microgranules following single dosing of either tablets (2 x 500 mg) or a new 1 g sachet (unit dose, microgranules in a foil bag). METHODS: A randomized crossover study in eight healthy volunteers was undertaken. Both formulations were radiolabelled by neutron activation and dosed in the fasted state. Location of the preparations in the bowel was assessed over 24 h by scintigraphy. RESULTS: Dissolution testing at pH 7.5 showed comparable in vitro mesalazine release properties for the tablet and sachet preparations. In vivo disposition of the microgranules administered as either tablets or sachet was comparable in terms of gastric emptying, small intestinal transit and colon arrival. CONCLUSIONS: Pentasa sachets 1 g unit dose offers the same release of mesalazine as Pentasa 500 mg tablets. Drug release occurs throughout the gastrointestinal tract from stomach to colon, with the advantage of fewer oral doses and ease of swallowing.