Oesophageal transit, disintegration and gastric emptying of a film-coated risedronate placebo tablet in gastro-oesophageal reflux disease and normal control subjects

Background: Risedronate sodium is a pyridinyl bisphosphonate, proven effect ive for the treatment and prevention of postmenopausal osteoporosis and glu cocorticoid-induced osteoporosis and Paget's disease of the bone. Aim: To compare the oesophageal transit, disintegration and gastric emptyin g of the commercial film-coated risedronate tablet in subjects with gastro- oesophageal reflux disease (GERD) and normal control subjects. Methods: A total of 30 subjects, 15 patients with GERD and 15 age- and sex- matched, normal control subjects, participated in a single-centre, open-lab el, comparative gamma scintigraphy study. The GERD subjects had active eros ive oesophagitis within 4 weeks prior to dosing. Results: The mean oesophageal transit (GERD, 4.4 s; controls, 3.1 s), mean disintegration (GERD, 21.8 min; controls, 19.2 min) and mean gastric emptyi ng (GERD, 15.9 min; controls, 15.0 min) were similar in the two subject gro ups. The oesophageal transit is rapid and given the rapid disintegration an d gastric emptying, oesophageal contact occurring via reflux of risedronate was unlikely since most, if not all, of the dosage form exited from the st omach within 30 min. Conclusions: The oval shape and film-coating on the commercial risedronate tablet promotes rapid oesophageal transit and minimizes oesophageal contact , even in the high-risk GERD population.