title: A liquid chromatography-mass spectrometry assay method for simultaneous determination of amiodarone and desethylamiodarone in rat specimens.
abstract: A liquid chromatographic-mass spectrometry (LC/MS) assay method was developed for the determination of amiodarone and desethylamiodarone in rat specimens. Analytes were extracted using liquid-liquid extraction in hexane. The LC/MS system consisted of a Waters Micromass ZQtrade mark 4000 spectrometer with an autosampler and pump. A C(18) 3.5 microm (2.1 x 50 mm) column heated to 45 degrees C was used for separation. The mobile phase consisted of methanol and 0.2% aqueous formic acid pumped at 0.2 mL/min as a linear gradient. Components eluted within 12 min. The concentrations of ethopropazine (internal standard), desethylamiodarone and amiodarone were monitored for m/z of 313.10, combination of 546.9 and 617.73, and 645.83, respectively. In plasma (0.1 mL), linearity was achieved between the peak area ratios and concentrations over the range of 2.5-1000 ng/mL for both amiodarone and desethylamiodarone (r(2) > 0.999). The intraday and interday CV were equal or less than 18%, and mean error was <12%. Similarly, in homogenates containing 0.1 g of rat tissue, linearity was observed in standards ranging from 5 to 5000 ng/g. The method was successfully used to measure tissue and plasma concentrations of drug. The validated lower limit of quantitation was 2.5 ng/mL for drug and metabolite, based on 0.1 mL of plasma.
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2N8.
authors.forename: Anooshirvan
authors.initials: A
authors.lastname: Shayeganpour
authors.forename: Vishwa
authors.initials: V
authors.lastname: Somayaji
authors.forename: Dion R
authors.initials: DR
authors.lastname: Brocks
mesh_terms: D000638:Amiodarone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000032:analysis* / Q000493:pharmacokinetics; D000818:Animals; D002138:Calibration / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007275:Injections, Intravenous; D016014:Linear Models; D015394:Molecular Structure; D010640:Phenothiazines / Q000592:standards; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014018:Tissue Distribution
chemical_list: D010640:Phenothiazines; C084820:profenamine; C036116:desethylamiodarone; D000638:Amiodarone