Esophageal transit of risedronate cellulose-coated tablet and gelatin capsule formulations

Risedronate sodium is an orally active antiresorptive agent and a member of the pyridinyl class of bisphosphonates. It has been approved for the treat ment of Paget's disease of the bone and is under development as a chronic t herapy for the treatment and prevention of osteoporosis. A novel cellulose film-coated tablet formulation was developed to optimize esophageal transit of this bisphosphonate. The aim of the present study was to compare the es ophageal transit of the film-coated tablet formulation of risedronate with its original gelatin capsule dose form. A total of 25 elderly, healthy volu nteers (mean 66 years), who were dysphagia-free, participated in this rando mized cross-over study. On separate occasions, volunteers swallowed radiola beled placebo formulations with 50 mi water. Dynamic images with participan ts in a sitting position were recorded for 10 min using a gamma camera. Sci ntigraphic imaging showed a delay in esophageal transit (greater than 15 s) in 28% of patients in the capsule group but in none of the tablet group (P <0.05). The mean transit times of the capsules and tablets were 23.8 and 3 .3 s, respectively. Esophageal transit of film-coated tablets was faster th an gelatin capsules, suggesting that film-coated tablets would be the appro priate formulation for all pivotal trials with risedronate and for subseque nt commercialization. (C) 1999 Elsevier Science B.V. All rights reserved.