Pharmacokinetics of lansoprazole injection in healthy volunteers

Objective To determine the pharmacokinetics in healthy volunteers following intravenous administration of lansoprazole.Methods A three-way crossover Latin square design was applied.Twelve healthy volunteers were randomized to administer a single dose of lansoprazole at 15,30 and 60 mg,respectively.Wash-out period lasted a week.The concentration of lansoprazole in human plasma was determined by HPLC-UV.The main pharmacokinetic parameters were calculated with DAS Ver 2.1.Results The pharmacokinetics of lansoprazole fit a two-compartment open model.The main parameters of a single dose were as follows(low,medium,and high):t1/2(1.76±1.43),(1.21±0.4)and(1.86±1.29)h;Cmax(0.92±0.33),(2.05±0.59)and(4.04±0.55)μg·mL-1;AUC0-10h(3.41±2.14),(6.25±3.55)and(11.65±5.96)h·μg·mL-1;AUC0-∞(7.67±6.37),(9.21±7.13)and(14.68±10.01)μg·h·mL-1;V(5.95±5.18),(6.32±3.74)and(5.26±6.03)L;CL(3.98±4.38),(4.81±2.18)and(5.43±2.43)L·h-1 respectively.Conclusion The process of lansoprazole in the dosage range of 15-60 mg fits the linear dynamic feature.There are great inter-individual variations in the metabolism of lansoprazole in humans due to the close relation with the gene polymorphism of CYP2C19,which should be personalized when taking medicine.