Determination of pharmacokinetic parameters of omeprazole based on distribution equilibrium / 西安交通大学学报(医学版)

ABSTRACT

Objective: To determine the pharmacokinetic parameters based on distribution equilibrium theory by establishing the blood drug concentration-time curve of single elimination phase. Methods:Rats were intravenously infused with omeprazole at andante constant rate. Blood was collected at different time points during infusion, and drug concentration in plasma was detected by HPLC. Pharmacokinetic parameters were calculated with GraphPrism 6.0 software. Results: The concentration-time curve of omeprazole during intravenous infusion showed a first-order exponential relationship. The increase of plasma omeprazole concentration was rapid at the initial stage of the infusion and then became gradually slow as time went on. After 5 half lives a steady state was reached. The elimination rate constant (K) of omeprazole in rats was (2.95±0.67)h-1. The half-life was (15±4)min. The apparent volume of distribution was (0.30±0.17)L, and the drug clearance was (0.83±0.33)L/h. Conclusion: The distribution of the drug in the body is basically balanced during the process of andante constant-rate intravenous infusion, and there is no interference of distribution. The measured pharmacokinetic parameters are closer to the reality.