title: Measurement of bumetanide in plasma and urine by high-performance liquid chromatography and application to bumetanide disposition.
abstract: A high-performance liquid chromatographic method for the measurement of bumetanide in plasma and urine is described. Following precipitation of proteins with acetonitrile, bumetanide was extracted from plasma or urine on a 1-ml bonded-phase C18 column and eluted with acetonitrile. Piretanide dissolved in methanol was used as the internal standard. A C18 Radial Pak column and fluorescence detection (excitation wavelength 228 nm; emission wavelength 418 nm) were used. The mobile phase consisted of methanol-water-glacial acetic acid (66:34:1, v/v) delivered isocratically at a flow-rate of 1.2 ml/min. The lower limit of detection for this method was 5 ng/ml using 0.2 ml of plasma or urine. Nafcillin, but not other semi-synthetic penicillins, was the only commonly used drug that interfered with this assay. No interference from endogenous compounds was detected. For plasma, the inter-assay coefficients of variation of the method were 7.6 and 4.4% for samples containing 10 and 250 ng/ml bumetanide, respectively. The inter-assay coefficients of variation for urine samples containing 10 and 2000 ng/ml were 8.1 and 5.7%, respectively. The calibration curve was linear over the range 5-2000 ng/ml.
authors.affiliation: Division of Pediatric Clinical Pharmacology, University of Arkansas for Medical Sciences, Little Rock.
authors.forename: T G
authors.initials: TG
authors.lastname: Wells
authors.forename: I R
authors.initials: IR
authors.lastname: Hendry
authors.forename: G L
authors.initials: GL
authors.lastname: Kearns
mesh_terms: D002034:Bumetanide / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D013050:Spectrometry, Fluorescence
chemical_list: D002034:Bumetanide