Pharmacokinetics and bioavailability in healthy Chinese volunteers of a novel rabeprazole sterile powder formulation for injection.

Rabeprazole sterile powder for injection (RSPI) is a new formulation, compared with rabeprazole enteric coated tablets. The aim of this study was to evaluate the pharmacokinetic properties and bioavailability of RSPI in healthy Chinese volunteers. Pharmacokinetic studies included an ascending single dose of 10, 20, 40 mg, and a multiple doses of 20 mg. A bioavailability study was evaluated following a single dose of 20 mg between RSPI and Pariet® Pharmacokinetic parameters of rabeprazole given in each treatment period were calculated using non-compartmental analysis. In the PK study, after a single intravenous dose of 10, 20, and 40 mg, the main pharmacokinetic parameters for rabeprazole were as follows: Cmax 566.88, 897.23, 2,171.6 ng/mL; AUClast/794.31, 1,122.76, 2,446.85 ng×h/mL, respectively. After multiple doses of 20 mg, the main pharmacokinetic parameters for rabeprazole were Cmax 991.90 ng/mL, AUClast 1,261.08 ng×h/mL. In the BA study, after a single oral dose of Pariet® 20 mg, the main pharmacokinetic parameters for rabeprazole were Cmax 582.74 ng/mL, AUClast 1,135.5 ng×h/mL. RSPI produced a less-than-proportional increase in exposure with increasing dose in healthy subjects. The accumulation ratio was 1.0, suggesting RSPI displayed no accumulation after repeated administration. The bioavailability of RSPI was increased by ~ 11% as measured by AUClast compared with Pariet® after a single oral administration.