Pharmacokinetic and Bioequivalence Study of Eldecalcitol Soft Capsules in Healthy Chinese Subjects

Eldecalcitol is a novel active vitamin D₃ 1,25(OH)₂ D₃ derivative used in the treatment of osteoporosis. To investigate and compare the pharmacokinetic and bioequivalent profiles of two eldecalcitol soft capsule formulations at a single dose of 0.75 µg in healthy Chinese volunteers, we conducted a randomized single-dose, open-label, two-period crossover study under fasting and fed conditions. Eligible subjects were randomly assigned to receive reference eldecalcitol soft capsules or test capsules in the first treatment period and to receive another formulation in the second period. Serial blood samples were collected for pharmacokinetic analysis. Adverse events were recorded. In total, 28 healthy subjects were enrolled in the fasting trial and 30 subjects were enrolled in the fed trial. The geometric mean ratios of the test formulation to the reference formulation for C_max , AUC_0-t , and AUC_0-∞ were 94.2%, 94.0%, and 103.3%, respectively, under fasting conditions and 100.1%, 97.3%, and 96.0%, respectively, under fed conditions. No severe adverse events were observed. The results showed that the test and reference eldecalcitol formulations were bioequivalent and well tolerated in healthy Chinese subjects under fasting and fed conditions.