title: Rapid quantification of amlodipine enantiomers in human plasma by LC-MS/MS: application to a clinical pharmacokinetic study.
abstract: A rapid, simple, specific and sensitive LC-MS/MS method has been developed and validated for the enantiomeric quantification of amlodipine (AML) isomers [R-amlodipine (R-AML) and S-amlodipine (S-AML)] with 200 μL of human plasma using R-AML-d4 and S-AML-d4 as corresponding internal standards as per regulatory guidelines. A simple liquid-liquid extraction process was used to extract these analytes from human plasma. The total run time was 3.5 min and the elution of R-AML, S-AML, R-AML-d4 and S-AML-d4 occurred at 1.62, 2.51, 1.63 and 2.53 min, respectively. This was achieved with a mobile phase consisting of 0.2% ammonia-acetonitrile (20:80, v/v) at a flow rate of 1 mL/min on a Chiralcel OJ RH column. A linear response function was established for the range of concentrations 0.1-10 ng/mL (r >0.998) for each enantiomer. The intra- and inter-day precision values for both enantiomers met the acceptance criteria. Both enantiomers were stable in a set of stability studies, viz. bench-top, auto-sampler, freeze-thaw cycles and long-term. The current assay was successfully applied to a pharmacokinetic study to quantitate AML enantiomers following oral administration of 10 mg AML tablet to humans.
authors: Analytical Research and Development, Novel Laboratories Inc., Somerset, NJ 08873, USA.
authors: Kishore Kumar
authors: KK
authors: Hotha
authors: Swapan
authors: S
authors: Roychowdhury
authors: Ramesh
authors: R
authors: Mullangi
authors: L K
authors: LK
authors: Ravindranath
mesh_terms: D017311:Amlodipine / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*; D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D016014:Linear Models; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D017311:Amlodipine
keywords: LC-MS/MS; amlodipine; enantiomers; human plasma; method validation; pharmacokinetics