HPLC-MS in evaluating bioequivalence of two kinds of aniracetam capsules in healthy volunteers

Objective To establish a HPLC-MS method for determinating the concentration of 4-p-anisamidobutyric acid(ABA),the main active metabolite of aniracetam capsules in the plasma,and to compare the bioequivalence of two aniracetam capsules in healthy volunteers.Methods Twenty-four healthy male volunteers were randomly given an oral single dose of 200 mg test or reference aniracetam capsules in a crossover manner.The concentrations of ABA were assayed by HPLC-MS at different time points.The main pharmacokinetic parameters and the relative bioavailability of two preparations were calculated,and their bioequivalence was evaluated.Results The pharmacokinetic parameters of test and reference preparations were as fol1ows: Cmax being(9.30 ± 5.13) and(8.70 ±3.17) μg/ml;tmaxbeing(38.41 ±17.89) and(39.09 ± 19.92) min;t1/2 being(37.21 ± 10.51) and(38.45 ± 9.24) min;AUC0-t being(555.21 ± 157.10) and(545.39 ± 97.22) μg/(ml.min),and AUC0-∞ being(566.24 ± 158.01) and(554.71 ± 100.32) μg/(ml.min),respectively.Relative bioavailability F0-t and F0-∞ values of the test preparation were(101.22 ± 17.17) % and(101.52 ± 16.63) %,respectively.No significant differences were found in the main pharmacokinetic parameters between the two preparations.Conclusion The two aniracetam preparations tested in the present study are bioequivalent.