Development and validation of a method for quantitative determination of valsartan in human plasma by liquid chromatography-tandem mass spectrometry

A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of valsartan in human plasma was developed and validated. A 0.5 ml aliquot was extracted using solid-phase extraction in an Empore(R) high performance extraction disk plate, universal resin 96-well formal. The estimated calibration range of the method was 2-2000 ng/ml. The method was fully validated with intra-day mean accuracy and precision of 94.8-107% and 2.19-5.40% and inter-day mean accuracy and precision of 93.5-105% and 1.87-5.67%, respectively. No significant loss of valsartan in processed samples was confirmed in processed samples for up to 24h at 10 degrees C. Sample dilution up to 50-fold with blank human plasma provided acceptable analyses. No interference peaks or matrix effects were observed. No effect of QC sample location results was observed in a 96-well plate. This LC-MS/MS technique was found to improve quantitative determination of valsartan allowing its pharmacokinetic evaluation with clinically relevant doses. (C) 2007 Elsevier B.V. All rights reserved.