Pharmacokinetics and Pharmacodynamics of Esomeprazole/Sodium Bicarbonate Immediate-Release Capsules in Healthy Chinese Volunteers: A Cross-Over, Randomized Controlled Trial

Introduction Esomeprazole delayed release tablets (ESO) are one of the most effective treatments for acid-related disorders. The purpose of this study is to compare the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of an immediate-release capsule formulation containing esomeprazole 20 mg and sodium bicarbonate 1100 mg (IR-ESO) compared to those of the esomeprazole delayed release tablet 20 mg (ESO). In addition, the impact of CYP2C19 gene polymorphisms on PK and PD was evaluated. Methods A single-center, open-label, randomized, 2-treatment, 2-sequence, and 2-period crossover study was conducted in 40 healthy Chinese subjects. Subjects received either IR-ESO or ESO for 5 days. After single- and multiple-dosing administration, blood samples were collected for PK analysis, and intragastric pH was assessed by 24-h pH monitoring. The CYP2C19 gene polymorphisms were analyzed by Sanger sequencing. Results The geometric mean ratios (90% confidence interval) [GMR (95%CI)] of IR-ESO/ESO for AUC(inf) [single dose: 103.60% (96.58%, 111.14%), multiple doses: 101.65% (97.88%, 105.57%)] were within the range of 80.00-125.00%. The AUC(inf) showed an increasing trend between CYP2C19 extensive metabolizer (EM), intermediate metabolizer (IM), and poor metabolizer (PM) after single-dose and multiple-dose administration (p < 0.05). The GMR (95%CI) of IR-ESO/ESO for 24-h integrated gastric acidity from baseline [single dose: 101.07% (96.56%, 105.78%), multiple doses: 101.24% (97.74%, 104.86%)] were within the range of 80.00-125.00%. The percentage changes in 24-h integrated gastric acidity from baseline was significant difference between EM, IM, and PM after single-dose IR-ESO and ESO (p < 0.05). Drugs were all well tolerated, and there were no significant differences in adverse events between IR-ESO and ESO. Conclusion This study showed that IR-ESO can inhibit the secretion of gastric acid rapidly and continuously, and that the PK and PD of IR-ESO are affected by CYP2C19 genotypes. The GMR (95% CI) of IR-ESO/ESO for AUC(inf) and the percentage changes in 24-h integrated gastric acidity from baseline were all within the range of 80.00-125.00%.

Automated summary

The study demonstrates that IR-ESO effectively inhibits gastric acid secretion and its PK and PD are influenced by CYP2C19 genotypes. The AUC(inf) and percentage changes in 24-h integrated gastric acidity from baseline for IR-ESO/ESO are within the range of 80.00-125.00%, with significant differences between different CYP2C19 genotypes.