title: Quantification of tizanidine in human plasma by liquid chromatography coupled to tandem mass spectrometry.
abstract: A simple, sensitive and rapid high-performance liquid chromatography/positive ion electrospray tandem mass spectrometry (MS/MS) method was developed and validated for the assay of tizanidine in human plasma. Following liquid-liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed-phase column and analyzed by MS/MS in the selected reaction monitoring mode. The assay exhibited a linear dynamic range of 50-5000 pg/mL for tizanidine in human plasma. The lower limit of quantification was 50 pg/mL with a relative standard deviation of less than 13%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.5 min for each sample made it possible to analyze more than 300 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies.
authors.affiliation: Biopharmaceutical Research, Suven Life Sciences Ltd., Serene Chambers, Road #7, Banjara Hills, Hyderabad 500 034, India. ramakrishna_nirogi@yahoo.co.in
authors.forename: Ramakrishna V S
authors.initials: RV
authors.lastname: Nirogi
authors.forename: Vishwottam N
authors.initials: VN
authors.lastname: Kandikere
authors.forename: Manoj
authors.initials: M
authors.lastname: Shukla
authors.forename: Koteshwara
authors.initials: K
authors.lastname: Mudigonda
authors.forename: Santosh
authors.initials: S
authors.lastname: Maurya
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003000:Clonidine / Q000031:analogs & derivatives* / Q000097:blood; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: C023754:tizanidine; D003000:Clonidine