Rapid and Sensitive LC-MS/MS Method for Simultaneous Determination of Three First-Line Oral Antituberculosis Drug in Plasma

Abstract A bioanalytical method for simultaneous quantification of isoniazid (INH), pyrazinamide (PZA) and ethambutol (EMB) in plasma was developed validated using high-performance liquid chromatography with tandem mass spectrometry. After extracted by protein precipitation acetonitrile, the analytes were separated on a Waters XBridge Amide column isocratic elution acetonitrile 5 mM ammonium acetate solution containing 0.3% formic acid (77:23, v/v) at flow rate 0.5 mL/min. The detection carried out triple quadrupole spectrometer equipped an electrospray ionization source positive mode monitoring selected ion transitions m/z 205.2 → 116.1, 137.9 121.2, 124.3 78.9 213.1 122.4 EMB, INH, PZA EMB-d8 Internal standard (IS), respectively. calibration curves linear over range 0.0125–2.00 μg/mL 0.0625–10.0 INH 0.250–40.0 PZA. Neither cross-analytes inter-conversion nor matrix effects observed. intra- inter-assay precision (%RSD) values within 8.80%, accuracy (%RE) ranged from −11.13 to 13.49%, indicating that well acceptable limits variation. would be helpful analysis samples clinical pharmacokinetics therapeutic drug monitoring.