Comparison of the pharmacokinetics, safety, and tolerability of vitamin D3 in DP-R206 (150-mg ibandronate/24,000-IU vitamin D3 tablet) and as monotherapy (24,000 iu) in healthy male Korean adults

Abstract

Background: Combined treatment with a bisphosphonate and vitamin D has been proposed for postmenopausal osteoporosis. A new, fixed-dose combination tablet of ibandronate plus vitamin D3 has been developed for monthly administration to treat postmenopausal osteoporosis.

Objectives: The main objective of the present study was to compare the pharmacokinetics of vitamin D3 administered in 2 forms: a newly developed ibandronate 150-mg/vitamin D3 24,000-IU tablet (DP-R206, test drug) and a stand-alone vitamin D3 24,000-IU tablet (reference drug). A secondary objective was to evaluate the safety and tolerability of DP-R206 in healthy adult male Korean volunteers.

Methods: This study was a single-dose, open-label, randomized-sequence, 2-treatment, 2-way crossover trial. Blood samples were collected from 24 hours' predose to 120 hours' postdose. The plasma concentrations of vitamin D3 were analyzed by using a validated HPLC-MS/MS method. Pharmacokinetic parameters were calculated, and the 90% CIs of the ratios of the geometric means of the parameters were determined from the logarithmically transformed data by using ANOVA.

Results: Thirty-sex healthy adult male Korean volunteers with a mean (SD) age of 25.8 (2.7) years, a mean height of 174.0 (5.9) cm, and a mean weight of 69.1 (6.2) kg were enrolled; 29 participants completed the study. The 90% CIs of the ratios of the geometric means (test drug/reference drug) of the baseline-corrected Cmax, AUC0-last, and AUC0-∞ values were 0.93 to 1.24, 0.89 to 1.19, and 0.87 to 1.18, respectively. The 90% CIs of the ratios of the geometric means (test drug/reference drug) of the baseline-uncorrected Cmax, AUC0-last, and AUC0-∞ values were 0.93 to 1.24, 0.88 to 1.19, and 0.87 to 1.18, respectively. Eighty-four adverse events (AEs) were reported in 24 of 32 subjects receiving DP-R206, and 14 AEs were reported in 8 of 29 subjects receiving the vitamin D3 24,000-IU tablet. All of the subjects who experienced AEs recovered without sequelae, and no serious AEs were observed.

Conclusions: The vitamin D3 pharmacokinetics were similar for DP-R206 and the 24,000-IU vitamin D3 tablet. DP-R206 was well tolerated.

Trial registration: ClinicalTrials.gov NCT01577849.

Keywords: ibandronate; osteoporosis; pharmacokinetics; vitamin D(3).