Simultaneous Determination of Valsartan and Hydrochlorothiazide in Human Plasma by LC-MS/MS Method
A rapid, selective and specific liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for simultaneous quantification of valsartan and hydrochlorothiazide in human plasma. After a solid phase extraction, the analytes were separated on an Ascentis express C18 column using Acetonitrile: Methanol: 10 mM ammonium Formate (5:85:10) as mobile phase at a flow rate of 0.400 mL/min with 10 μL of sample. Valsartan and hydrochlorothiazide were eluted at 1.0 ± 0.30 min in the duration of 2.50 min and the selected reaction monitoring was specific for mass detection employing negative electro spray ionization. The precursor to product ion transitions of m/z 433.8 → 178.80 and m/z 295.80 → 204.90 were used to quantify valsartan and hydrochlorothiazide respectively. The method was linear in the concentration range of 20.00–10019.33 ng/mL for valsartan and 3.76– 303.53 ng/mL for hydrochlorothiazide. Intra-day and inter day precision (%CV) and accuracy (% Nominal) for quality control samples (55.95, 4662.30 and 7875.51 ng /mL for valsartan and 11.22, 136.80 and 232.89 ng /mL for hydrochlorothiazide) ranged between 2.05 to 3.60% for valsartan 2.75- 2.95% for hydrochlorothiazide. and % nominal ranged between 100.30 to 108.54% for valsartan and 95.05 to 101.14% for hydrochlorothiazide respectively. Extraction recovery of valsartan from plasma was in the range 69.84 – 71.05%, Mean recovery is 70.35% and 69.74 – 69.92%, mean recovery is 69.80% for hydrochlorothiazide respectively.