Pharmacokinetics and bioequivalence of flunarizine hydrochloride capsules in healthy volunteers

Objective To establish an HPLC-MS/MS method for the determination of flunarizine in human plasma,and investigate the pharmacokinetics and bioequivalence of flunarizine in healthy volunteers.Methods A single oral dose of 20 mg flunarizine of each kind of capsules was given to 20 male healthy volunteers respectively in an open,randomized crossover study.The concentration of flunarizine in the plasma was determined by HPLC-MS/MS.DAS program was used to calculate the pharmacokinetic parameters and evaluate the bioequivalence of the two formulations.Results The main pharmacokinetic parameters of the test and reference flunarizine capsules were as follows:tmax was(2.43±0.75) and(2.40±0.77)h,Cmax was(56.9±18.5) and(54.8±18.9) μg·L-1,t1/2 was(6.68±1.74) and(5.99±1.77)h,AUC0-t was(382±134) and(405±151) μg·h·L-1,and AUC0-∞ was(417±149) and(436±167) μg·h·mL-1,respectively.The relative bioavailability was(96.9±16.9)%.Conclusion The method is rapid,specific and accurate with reliable results.The test capsule is bioequivalent to the reference capsule.