An Open‐Label, Randomized Pharmacokinetic Study of 2 Formulations of Eldecalcitol Capsules Following Single Oral Administration in Healthy Chinese Volunteers Under Fasting and Fed Conditions

Eldecalcitol is an active vitamin D-3 derivative that is used for the prevention and treatment of osteoporosis. The objectives of this study were to evaluate the bioequivalence and safety of 2 formulations of eldecalcitol capsule (0.75 mu g) in healthy Chinese male and female volunteers, as well as to investigate the food effect on the pharmacokinetics of this drug. An open label, randomized, 3-period, 3-sequence, reference replicated crossover clinical study was performed in 27 healthy Chinese volunteers under fasting conditions, while a 2-way crossover study was carried out in 28 healthy Chinese volunteers under fed conditions. Volunteers were administered a single oral dose of 0.75 mu g eldecalcitol after fasting overnight. Blood samples were collected at scheduled time points from 0 to 168 hours after administration of eldecalcitol. The 90%CIs of the test/reference geometric mean ratio (area under the plasma concentration-time curve and maximum plasma concentration) of eldecalcitol after a single-dose administration were within the acceptance criteria based on the average bioequivalence method. The time to maximum concentration of the test and reference formulations were elevated by approximate to 2.3-fold and 1.7-fold, respectively, after a high-fat meal. Only mild and transient adverse events were reported in this study, and no severe adverse events occurred. These results indicated that the 2 formulations of eldecalcitol were bioequivalent under both fasting and fed conditions. Food intake prolonged the oral absorption of eldecalcitol but did not significantly influence systemic exposure.