Pharmacokinetic characteristics of ibandronate and tolerability of DP-R206 (150 mg Ibandronate/24,000 IU Vitamin D₃) compared to the ibandronate (150 mg) monotherapy in healthy adults

Ibandronate (a bisphosphonate) is commonly used as an treatment of osteoporosis in combination with vitamin D. Monthly DP-R206-a novel, fixed-dose combination tablet (150 mg ibandronate/ 24,000 IU vitamin D₃)-was recently developed to enhance patient compliance. This open, randomized, two-period crossover study was conducted to compare the pharmacokinetics of ibandronate when administered as DP-R206 or 150 mg ibandronate to healthy adult volunteers. Each volunteer was randomly allocated to receive single-dose DP-R206 or ibandronate with a 28-day washout period between treatments. Blood samples were assessed using pharmacokinetic analysis. Plasma ibandronate concentrations were determined using liquid chromatography-tandem mass spectrometry. Safety and tolerability assessments were performed throughout the study. In total, 103 participants received the study drugs and 72 participants completed the study. The geometric mean ratios (DP-R206/ibandronate) of the maximum concentration (C_max) and the area under the plasma concentration time curve from time zero to the last concentration (AUC_last) values were 0.959 (90% CI: 0.820–1.120) and 0.924 (90% CI: 0.805–1.060), respectively. The frequencies of adverse events (AEs) and drug reactions were similar between treatment groups, and all AEs were recovered without sequalae. Ibandronate pharmacokinetics, tolerability, and safety are comparable when administered to healthy individuals, regardless if administered as DP-R206 or ibandronate.