title: Development and Validation of a LC-MS/MS Method for the Simultaneous Estimation of Amlodipine and Valsartan in Human Plasma: Application to a Bioequivalence Study.
abstract: A reliable, simple, and robust liquid chromatography-tandem mass spectro-metric (LC-MS/MS) method has been developed and validated that employs solid-phase extraction for the simultaneous estimation of amlodipine and valsartan in human K3EDTA plasma using amlodipine-d4 and valsartan-d9 as internal standards. Chromatographic separation of amlodipine and valsartan was achieved on the Luna C18 (2)100A (150 × 4.6 mm, 5 μm) column using acetonitrile: 5 mM ammonium formate solution (80:20, v/v) as the mobile phase at a flow rate of 0.8 mL/min in isocratic mode. Quantification was achieved using an electrospray ion interface operating in positive mode, under multiple reaction monitoring (MRM) conditions. The assay was found to be linear over the range of 0.302-20.725 ng/mL for amlodipine and 6.062-18060.792 ng/mL for valsartan. The method has shown good reproducibility, as intra- and interday precisions were within 10% and accuracies were within 8% of nominal values for both analytes. The method was successfully applied for the bioequivalence study of amlodipine and valsartan after oral administration of a fixed dose of the combination. Additionally, as required by the current regulatory bodies, incurred sample reanalysis was performed and found to be acceptable.
authors: Clinical Pharmacology and Pharmacokinetics, Ranbaxy Research Laboratories, Gurgaon, India.
authors: Hemanth
authors: H
authors: Jangala
authors: Clinical Pharmacology and Pharmacokinetics, Ranbaxy Research Laboratories, Gurgaon, India.
authors: Poonam
authors: P
authors: Vats
authors: Clinical Pharmacology and Pharmacokinetics, Ranbaxy Research Laboratories, Gurgaon, India.
authors: Arshad Hussain
authors: AH
authors: Khuroo
authors: Clinical Pharmacology and Pharmacokinetics, Ranbaxy Research Laboratories, Gurgaon, India.
authors: Tausif
authors: T
authors: Monif
keywords: Amlodipine; Bioequivalence; Liquid chromatography-mass spectrometry; Non compartmental pharmacokinetics; Solid phase extraction; Valsartan