title: High-performance liquid chromatographic determination of rivastigmine in human plasma for application in pharmacokinetic studies.
abstract: A simple and reproducible HPLC method with spectrophotometric detection was developed for determination of rivastigmine in human plasma. Liquid-liquid extraction of rivastigmine and donepezil (as internal standard) from plasma samples was performed with 1-butanol/n-hexane (2:98 v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using a Silica column (250 mm × 4.6 mm, 5 μm) under isocratic elution with acetonitrile-50 mM aqueous sodium dihydrogen phosphate (17: 83 v/v, pH 3.1. Analyses were run at a flow-rate of 1.3 mL/min at of 50°C. The recovery was 90.8% and 95.7% for rivastigmine and the internal standard donepezil, respectively. The precision of the method was 2.6% to 9.1% over the concentration range of 0.5-16 ng/mL for rivastigmine in plasma with a linearity greater than 0.999. The method was specific and sensitive, with a quantification limit of 0.5 ng/mL and a detection limit of 0.2 ng/mL in plasma. The method was used for a bioequivalence study in healthy subjects.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Golestan University of Medical Gorgan, Iran. ; Department of Pharmacology, Neuroscience Research Center, Saheed Beheshti University of Medical Sciences and Health Services,Tehran,Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Amini
authors.affiliation: Department of Pharmacology, Neuroscience Research Center, Saheed Beheshti University of Medical Sciences and Health Services,Tehran,Iran.
authors.forename: Abolhassan
authors.initials: A
authors.lastname: Ahmadiani
keywords: HPLC; Liquid- liquis extraction; Pharmacokinetics; Rivastigmine; Spectrophotometric detection