Syed N Alvi
King Faisal Specialist Hospital & Research Center, Saudi Arabia
Title: Determination of amlodipine in human plasma by liquid chromatography–tandem mass spectrometry and its application to pharmacokinetic & bioequivalence studies
Biography
Biography: Syed N Alvi
Abstract
A rapid Liquid Chromatographic-Tandem Mass Spectrometric (LC-MS/MS) assay for the measurement of amlodipine level in human plasma was developed and validated. Amlodipine and tizanidine (IS) were extracted from plasma using mixture of dichloromethane and tertiary butyl methyl ether (1:3, v:v) and reconstituted with 100 µl mixture of methanol and water (1:1, v:v). The mobile phase consisted of acetonitrile and 0.1% formic acid (80:20, v:v). Analysis was performed at room temperature using a reversed phase Atlantis dC18 (2.1x100 mm, 3 µm) column. The components of interest were detected in the positive ion mode of electrospray ionization using transition 409.8 → 238.4 and 254.3 → 43.9 for amlodipine and the IS, respectively. The relationship between amlodipine concentration in plasma and peak height ratio of amlodipine to IS was linear 0.9868 in the range of 0.2–20 ng/ml; intra and inter-day accuracy between 101-114%, and coefficient of variations were ≤14.4%. The quantification limit of amlodipine in 0.5 ml plasma was 0.2 ng/ml and the detection limit was 0.1 ng/ml. The method was successfully validated and applied in a bioequivalence study of four tablet formulations of amlodipine.