Liquid chromatography tandem mass spectrometry method for quantification of topiramate in human plasma

A simple and reproducible liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method for determination of topiramate in human plasma was developed and validated. The plasma samples were prepared by liquid-liquid extraction (LLE) method which composed of methyl-t-butyl ether and hexane. Topiramate and amlodipine (internal standard; IS) were separated on Luna HST 2.5 µm C18 (50×3 mm.) column. The mobile phase consisted of acetonitrile and 10 mM ammonium acetate (90:10, v/v) at pH 4.0 was run under isocratic condition at a flow rate of 0.3 ml/min. The total run time was 2.5 min. Mass detection was performed in multiple reaction monitoring (MRM) mode under negative electrospray ionization (ESI). The mass transitions were monitored at m/z 337.93>77.78 for topiramate and m/z 406.92>295.10 for IS. The lower limit of quantification (LLOQ) was 10 ng/mL which demonstrated good sensitivity and specificity. The linearity range of the method was 10–3,000 ng/mL with the correlation coefficients (r) ≥ 0.995. The method was economical since it required only 200 µL of sample, 1 mL of solvent and 2 µL of injection volume.