Pharmacokinetic comparison of two bazedoxifene acetate 20 mg tablet formulations in healthy Korean male volunteers

Bazedoxifene, used as bazedoxifene acetate, is a selective estrogen receptor modulator that selectively affects the uterus, breast tissue, bone metabolism, and lipid metabolism by antagonizing or enhancing estrogens in the estrogen receptor in the tissue. This study was conducted as an open, randomized, two-period, two-treatment, crossover design to compare the pharmacokinetic (PK) characteristics and tolerability of two bazedoxifene tablets when administered to 50 healthy Korean male volunteers. Enrolled subjects were randomly allocated to 2 sequences of a single oral administration of a test drug and a reference drug, or vice versa with a 14-day washout period between the two doses. Serial blood samples were collected over 96 h for PK analysis. Plasma concentration of bazedoxifene was assayed using liquid chromatography-tandem spectrometry mass. Forty-five participants completed the study with no clinically relevant safety issues. The peak concentrations (C-max, mean +/- strandard deviation) of reference drug and test drug were 3.191 +/- 1.080 and 3.231 +/- 1.346 ng/mL, respectively, and the areas under the plasma concentration-time curve from 0 to the last measurable concentration (AUC(last)) were 44.697 +/- 21.168 ng.h/mL and 45.902 +/- 23.130 ng . h/mL, respectively. The geometric mean ratios of test drug to reference drug and their 90% confidence intervals for C-max and AUC(last) were 0.9913 (0.8828-1.1132) and 1.0106 (0.9345-1.0929), respectively. The incidence of adverse events between the two formulations was similar. The present study showed that PK and tolerability of two bazedoxifene tablet formulations were comparable when administered to healthy Korean male volunteers.