Simple and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for estimation of Balsalazide in human plasma

Abstract

A simple, rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the estimation of Balsalazide in human plasma. The drug and internal standard (ISTD), Paracetamol, were extracted from plasma by addition of hydrochloric acid (1 M) followed by liquid-liquid extraction with diethyl ether. The analytes were separated using a mobile phase of methanol-ammonium acetate (25 mM) (60:40, v/v) on Alltima-Grace C 18 (4.6 x 250 mm, 5.0 μm) column at a flow rate of 0.8 mL/min and analyzed by a triple-quadrupole mass spectrometer in negative ion multiple reaction monitoring (MRM) mode at transitions (m/z) of 356.1→240.0 for Balsalazide and 149.8→107.1 for ISTD using electrospray ionization (ESI). The total chromatographic run time was 4 min and the assay exhibited a linear dynamic range of 1.02 - 1003 ng/mL for Balsalazide in human plasma. The method was validated in terms of sensitivity, selectivity, recovery, linearity range, accuracy and precision, ruggedness, dilution integrity, stability and reinjection reproducibility. The limit of quantification was 1.02 ng/mL with precision of 3.34% and accuracy of 98.32%. The validated method was successfully employed to support the pharmacokinetic study of Balsalazide formulations in healthy human volunteers.