title: Determination of nimodipine in human plasma by HPLC-ESI-MS and its application to a bioequivalence study.
abstract: A simple, specific, and precise liquid chromatographic-electrospray ionization mass spectrometric (LC-ESI-MS) method has been developed for determination of nimodipine concentration in human plasma. The method involves the addition of 200 microL of saturated sodium bicarbonate (NaHCO(3)) solution to plasma to improve the extraction recovery, liquid-liquid extraction of nimodipine from plasma samples with anhydrous diethyl ether, simple reversed-phase chromatography, and ESI mass spectrometric detection in negative ion selected ion monitoring mode (SIM) using target [M-] ions at m/z 417 and m/z 359 for nimodipine and nitrendipine (internal standard, IS), respectively. A complete analytical run was achieved within 3.5 min. The limit of quantification was 0.5 ng/mL. The method was validated within a linear range of 0.5-100 ng/mL. The correlation coefficient for the calibration regression line was 0.9995 or better. Intra- and inter-batch accuracy and precision were acceptable. Analyte was stable in a battery of stability studies. The method has been successfully used in a bioequivalence study.
authors.affiliation: School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Desheng
authors.initials: D
authors.lastname: Zhai
authors.forename: Xijing
authors.initials: X
authors.lastname: Chen
authors.forename: Qiaoling
authors.initials: Q
authors.lastname: Yu
authors.forename: Hui
authors.initials: H
authors.lastname: He
authors.forename: Ya
authors.initials: Y
authors.lastname: Sun
authors.forename: Zidong
authors.initials: Z
authors.lastname: Gao
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Wang
authors.forename: De'en
authors.initials: D
authors.lastname: Han
authors.forename: Hui
authors.initials: H
authors.lastname: Ji
mesh_terms: D002121:Calcium Channel Blockers / Q000097:blood* / Q000493:pharmacokinetics; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D009553:Nimodipine / Q000097:blood* / Q000493:pharmacokinetics; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013810:Therapeutic Equivalency
chemical_list: D002121:Calcium Channel Blockers; D009553:Nimodipine