Pharmacokinetics and Pharmacodynamics of Lansoprazole/Sodium Bicarbonate Immediate-release Capsules in Healthy Chinese Subjects: An Open, Randomized, Controlled, Crossover, Single-, and Multiple-dose Trial

Proton pump inhibitors (PPIs) differ in onset of action and bioavailability. This trial was conducted to investigate the pharmacokinetics and pharmacodynamics of an immediate-release capsule formulation containing lansoprazole 30 mg and sodium bicarbonate 1100 mg (T preparation) in healthy Chinese subjects. This was an open, single-center, randomized, single and multiple oral doses, and two-period crossover study in 30 healthy subjects. After single- and multiple-dose oral administration, blood samples were obtained and lansoprazole concentration in serum was measured for pharmacokinetic analysis. Meanwhile, the intragastric pH was monitored continuously to evaluate the pharmacodynamics of the investigational drugs. The T-max of the T preparation was 0.5 hours, while the T-max of the R preparation was 1.5 hours after multiple doses, which indicated that the absorption speed of the T preparation was significantly faster than that of the R preparation. The same characteristics also existed after single-dose administration. The area under the curve (AUC)(ss) of the T preparation was bio-equivalent to that of the R preparation under steady state. The time percentage of intragastric pH > 4.0 for the T preparation was higher than that of the R preparation after 1 hour for both single- and multiple-dose. It suggested compared with R preparation, the time percentage of intragastric pH > 4.0 met the criteria for superiority after 1 hour administration for the T preparation. In addition, no serious adverse events occurred in this study. Across this study, the T preparation was better than the R preparation at improving drug absorption and increasing intragastric pH, and had a favorable safety profile.