Determination of Riluzole in Human Plasma by Ultra Performance Liquid Chromatography–Tandem Mass Spectrometry (UPLC – MS/MS) and its Application to a Pharmacokinetic Study

A rapid, sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometric (UPLC- MS/MS) method was developed and validated for the estimation of Riluzole in human plasma using Olanzapine as an internal standard. Riluzole and Internal standard were extracted from 0.5 mL plasma by solid phase extraction method. The analytical separation was carried out in a reverse liquid chromatography by using C18 (50 x 4.6mm 1.8,) 10mMAmmonium Acetate: Methanol (10:90) v/v at 0.5 mL/min at isocratic mode . The detection was performed on a triple quadruple tandem mass spectrometer by multiple reactions monitoring (MRM) mode via electro spray ionization (ESI) source. Analytes were monitored in multiple reactions monitoring mode using the respective [M+H] +ions, m/z 234.84/137.63 for Riluzole and m/z 313.15/256.14 for the internal standard, respectively. The proposed method was validated with linear range of 5 -1000ng/ml for Riluzole with a runtime 2.5 minutes. The %R.S.D of intra-day and inter-day assay was lower than 15%. For its sensitivity and reliability, the proposed method is particularly suitable for pharmacokinetic studies.