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 mesalaz ine 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 prolo nged-release microgranules following single dosing of either tablets (2 x 5 00 mg) or a new 1 g sachet (unit dose, microgranules in a foil bag). Methods: A randomized crossover study in eight healthy volunteers was under taken. Both formulations were radiolabelled by neutron activation and dosed in the fasted state. Location of the preparations in the bowel was assesse d over 24 h by scintigraphy. Results: Dissolution testing at pH 7.5 showed comparable in vitro mesalazin e release properties for the tablet and sachet preparations. In vivo dispos ition of the microgranules administered as either tablets or sachet was com parable in terms of gastric emptying, small intestinal transit and colon ar rival. Conclusions: Pentasa sachets 1 g unit dose offers the same release of mesal azine as Pentasa 500 mg tablets. Drug release occurs throughout the gastroi ntestinal tract from stomach to colon, with the advantage of fewer oral dos es and ease of swallowing.