Bioavailability of alendronate and vitamin D(3) in an alendronate/vitamin D(3) combination tablet

These studies were designed to demonstrate that the alendronate (ALN) component of an ALN/vitamin D(3) combination tablet was bioequivalent to the 70-mg ALN tablet and that the pharmacokinetic parameters of vitamin D(3) were similar with or without ALN. These were open-label, randomized, 2-part, 2-period, crossover studies. In part I, participants received either a single combination tablet or ALN 70 mg. In part II, participants received either a single combination tablet or vitamin D(3) alone. Results from part I showed that the geometric mean ratio (GMR) for total urinary excretion of ALN for both studies fell within the prespecified bioequivalence bounds. Results from part II showed that the pharmacokinetic profiles of vitamin D(3) with or without ALN were also similar. The combination tablets are bioequivalent to the ALN 70-mg tablet with respect to ALN bioavailability. The bioavailability of vitamin D(3) is similar in the combination tablets and when administered alone. No serious adverse experiences were reported.