Assess the Safety, Efficacy, and Pharmacokinetics of Immediate and Delayed Release Weekly Risedronate

Study to Assess the Efficacy, Safety and Pharmacokinetics of Risedronate Upon Oral Administration of a 35 mg Delayed-Release, a 50 mg Delayed-Release or a 35 mg Immediate-Release Administered Weekly for 13 Weeks to Postmenopausal Women

To compare the efficacy 50 mg delayed-release risedronate tablet, dosed immediately after breakfast, to a 35 mg immediate-release tablet, administered according to labeling instructions.

To compare the efficacy, based on the bone turnover marker (BTM) serum Type I collagen C-telopeptide (CTx), of a 50 mg delayed-release risedronate tablet, administered immediately after a typical breakfast, to that of a 35 mg immediate-release tablet, administered according to labeling instructions (ie, at least 30 minutes prior to breakfast) in postmenopausal women after 13 weeks of treatment.

Inclusion Criteria:

• In generally good health, as determined by medical history, physical examination, and laboratory test results
• Postmenopausal greater than 2 years, naturally or surgically based on medical history.

Exclusion Criteria:

• Used any of the following medications within 3 months prior to dosing or used any of the following medications for more than 1 month at any time within 6 months prior to dosing:

  • oral or parenteral glucocorticoids (5 mg prednisone or equivalent/day)
  • anabolic steroids
  • estrogens (oral, skin patch, or gel), except for low dose vaginal products or insertable estrogen ring, selective estrogen-receptor modulators, or estrogen-related drugs
  • progestins
  • calcitonin
  • vitamin D supplements
  • calcitriol, calcidiol, or alfacalcidol at any dose
  • any bisphosphonate
  • fluoride
  • strontium
  • parathyroid hormone, including teriparatide