[Pharmacokinetics and bioequivalence of trimebutine dispersive tablet in healthy subjects].

AIM:To develop an HPLC-ESI-MS assay for determination of trimebutine in human plasma and to investigate the pharmacokinetics and bioequivalence of two trimebutine tablets in human. METHODS:After being made alkaline with saturated sodium bicarbonate, plasma was extracted by cyclohexane and separated by HPLC on a reversed-phase C18 column with a mobile phase of 10 mmol x L(-1) ammonium acetate buffer solution (pH 3.5)-methanol (18:82). HPLC-ESI-MS was performed in the selected ion monitoring (SIM) mode using target ions at m/z 388 for trimebutine and m/z 280 for the internal standard (sibutramine, IS). The fragmentor voltage was 50 V. A randomized cross-over design was performed in 20 healthy volunteers. In the two study periods, a single 100 mg dose of each tablet was administered to each volunteer. RESULTS:Calibration curve was linear over the range of 0.3 - 150 microg x L(-1). The main pharmacokinetic parameters of T1/2, Tmax and Cmax were (9.2 +/- 2.8) h, (1.0 +/- 0.3) h and (40 +/- 20) microg x L(-1) for the reference tablet; (9.2 +/- 2.3) h, (0.9 +/- 0.4) h and (41 +/- 20) microg x L(-1) for the test tablet. The relative bioavalability of the test tablet was (97 +/- 13)%. The results of variance analysis and two one-sided t-test showed that there was no significant difference between the two formulations in the AUC and Cmax. CONCLUSION:The assay was proved to be sensitive, accurate and convenient. The two formulations were bioequivalent.