Mass Spectrometry

Biography

Biography: Kashyap N. Thummar

Abstract

A simple, sensitive and reliable liquid chromatography – tandem mass spectrometry (LC –MS/MS) method was developed for the quantification of topiramate (TOP) in human plasma by using the liquid–liquid extraction method. The method was developed and validated over the linearity range 15 – 3000 ng/mL with 0.2 mL of human plasma using niclosamide (IS) as an internal standard. The MS – MS ion transitions were monitored at m/z 338.20 – 78.20 and m/z 325.20 - 171.20 for TOP and IS in negative mode respectively. Chromatographic separation was achieved on Gemini C₁₈ (150 mm x 4.6 mm, 5 µm) column with an isocratic mobile phase composed of 2 mM ammonium acetate and acetonitrile in the ratio of 15:85 (v/v), at a flow-rate of 0.5 mL/min. This method demonstrated intra- and inter-day precision within 3.61 – 9.35% and 4.85 – 9.61% and accuracy within 93.09 – 105.24% and 92.46 – 104.40%. The extraction recoveries of TOP were over 89%. TOP was found to be stable throughout three freeze–thaw cycles, bench top and postoperative stability studies. The method is proved to be accurate and specific, and was successfully applied to the pharmacokinetic study in epileptic patients