title: Quantitative estimation of riluzole in human plasma by LC-ESI-MS/MS and its application to a bioequivalence study.
abstract: A novel simple, sensitive, selective, and rapid high-performance liquid chromatography coupled with tandem mass spectrometry method was developed and validated for quantification of riluzole in human plasma. The chromatography was performed by using a Zorbax-SB-C18 (4.6 x 75 mm, 3.5 microm) column , isocratic mobile phase 0.1% formic acid/acetonitrile (10:90 v/v), and an isotope-labeled internal standard (IS), [(13)C,(15)N(2)]riluzole. The extraction of drug and internal standard was performed by liquid-liquid extraction and analyzed by MS in the multiple reaction monitoring (MRM) mode using the respective [M+H](+) ions, m/z 235.0/165.9 for riluzole and m/z 238.1/169.0 for the IS. The calibration curve was linear over the concentration range 0.5-500.0 ng/ml for riluzole in human plasma. The limit of quantification (LOQ) was demonstrated at 0.5 ng/ml. The within-batch and between-batch precision were 0.6-2.3% and 1.4-5.7%, and accuracy was 97.1-101.1% and 98.8-101.2% for riluzole respectively. Drug and IS were eluted within 3.0 min. The validated method was successfully applied in a bioequivalence study of riluzole in human plasma.
authors.affiliation: Faculty of Pharmacy, Al-Jabal Al-Gharbi University, P.O. Box 13040, Gherian, Libya. drchandubaburao@gmail.com
authors.forename: Babu Rao
authors.initials: BR
authors.lastname: Chandu
authors.forename: Sreekanth
authors.initials: S
authors.lastname: Nama
authors.forename: Kanchanamala
authors.initials: K
authors.lastname: Kanala
authors.forename: Balasekhara Reddy
authors.initials: BR
authors.lastname: Challa
authors.forename: Rihana Parveen
authors.initials: RP
authors.lastname: Shaik
authors.forename: Mukkanti
authors.initials: M
authors.lastname: Khagga
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D018691:Excitatory Amino Acid Antagonists / Q000097:blood* / Q000493:pharmacokinetics; D006801:Humans; D057230:Limit of Detection; D012015:Reference Standards; D015203:Reproducibility of Results; D019782:Riluzole / Q000097:blood* / Q000493:pharmacokinetics; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013810:Therapeutic Equivalency
chemical_list: D018691:Excitatory Amino Acid Antagonists; D019782:Riluzole