Two-way crossover bioequivalence study of alendronate sodium tablets in healthy, non-smoking male volunteers under fasted conditions.

This study was conducted in order to assess the bioequivalence of two different formulations containing 70 mg alendronate sodium (CAS 121268-17-5) under fasted conditions. One hundred twenty-two healthy male volunteers were enrolled in an open label, randomized, crossover design with a wash-out period of 20 days in one study center. Urine samples were collected up to 36 h post-dose, and the concentrations of alendronic acid were determined using a high performance liquid chromatographic method with pre-derivatization and fluorescence detection (HPLC/FL) method. The mean Ae(0-t) were 604.24 +/- 348.73 microg and 627.36 +/- 327.99 microg, while the mean R(max) were 193.87 +/- 114.68 microg/h and 202.00 +/- 107.83 microg/h for the test and reference formulations, respectively. The T(max) of the test and reference tablets were 1.26 +/- 0.58 h and 1.26 +/- 0.51 h, respectively. No significant differences of pharmacokinetic parameters between the two studied formulations were found. The 90% confidence intervals for the primary target parameters, intra-individual ratios for Ae(0-t) and R(max) of alendronic acid, were between 0.86-1.00 and 0.85-1.01, respectively, and thus within the acceptance range for bioequivalence criteria. In the light of the present study it can be concluded that the test formulation is bioequivalent to the reference formulation.