title: Simultaneous Determination and Pharmacokinetics of Metolazone, Losartan and Losartan Carboxylic Acid in Rat Plasma by HPLC-ESI-MS-MS.
abstract: For the first time, we developed and validated a highly sensitive, selective and rapid HPLC-ESI-MS-MS method for simultaneous quantification of metolazone (MET), losartan (LOS) and its metabolite losartan carboxylic acid (LCA) in rat plasma. After solid-phase extraction, the analytes and internal standard (irbesartan) were extracted from 100 µL plasma sample on an Agilent Poroshell 120, EC-C18 (50 × 4.6 mm, i.d., 2.7 µm) column using 5 µL injection volume with a total run time of 3 min. Acidified methanol/water mixture was used as a mobile phase. The parent → product ion transitions for MET (m/z 366.0 → 258.9), LOS (m/z 423.2 → 207.0), LCA (m/z 437.0 → 235.1) and IS (m/z 429.2 → 207.0) were monitored on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring and positive ion mode. The method was found to be linear in the range of 0.05-250 for MET, 2-3,000 for LOS and 4-3,500 ng/mL for LCA. The method was validated with respect to selectivity, linearity, accuracy, precision, recovery and stability according to accepted regulatory guidelines. The described method was successfully applied to preclinical pharmacokinetic studies of analytes after an oral administration of mixture of MET (1 mg/kg) and LOS (10 mg/kg) in rats.
authors.affiliation: Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, India.
authors.forename: Ramkumar
authors.initials: R
authors.lastname: Dubey
authors.affiliation: Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, India manik@bitmesra.ac.in.
authors.forename: Manik
authors.initials: M
authors.lastname: Ghosh
authors.affiliation: Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, India.
authors.forename: Barij Nayan
authors.initials: BN
authors.lastname: Sinha
authors.affiliation: CERTARA, Translational Science Solutions, St. Louis, MI, USA.
authors.forename: Venkateswari
authors.initials: V
authors.lastname: Muthukrishnan
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D016014:Linear Models; D019808:Losartan / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*; D008297:Male; D008788:Metolazone / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D019808:Losartan; D008788:Metolazone