title: Rapid, high-sensitivity reversed-phase liquid chromatographic assay for 9-chloro-2-(2-furyl) [1,2,4]triazolo[1,5-c]quinazolin-5-imine and its oxo metabolite in plasma using fluorescence detection.
abstract: A rapid, sensitive and specific assay for 9-chloro-2-(2-furyl) [1,2,4]triazolo[1,5-c]quinazolin-5-imine (I) and its oxo metabolite (II) in plasma was developed and validated employing reversed-phase high-performance liquid chromatography with fluorescence detection. Sample preparation was achieved by a simple ethyl acetate extraction from plasma buffered at pH 10 (0.1 M boric acid-0.1 M potassium chloride). Chromatographic analyses were performed isocratically on a C18 column, with a mobile phase consisting of methanol-0.2 M sodium acetate buffer, pH 5.0 (67:33, v/v). Chromatographic run time was less than 8 min. The assay was linear (r greater than 0.9998) over the concentration range 1.50-10,000 ng/ml for both I and II; for individual studies, curves covering a range of two orders of magnitude were generally employed. Limits of detection for I and II were 0.5 and 1.0 ng/ml, respectively. A preliminary investigation of the plasma concentrations of I and II in the rat following a single 30 mg/kg oral dose demonstrated the applicability of the method for pharmacokinetic studies.
authors.affiliation: Research Department, Ciba-Geigy Corporation, Ardsley, NY 10502.
authors.forename: W F
authors.initials: WF
authors.lastname: Brubaker
authors.forename: E D
authors.initials: ED
authors.lastname: Williams
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D008297:Male; D058914:Purinergic Antagonists; D011799:Quinazolines / Q000097:blood / Q000378:metabolism* / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains; D013050:Spectrometry, Fluorescence; D014230:Triazoles / Q000097:blood / Q000378:metabolism* / Q000652:urine
chemical_list: D058914:Purinergic Antagonists; D011799:Quinazolines; D014230:Triazoles; C062648:CGS 15696; C052410:9-chloro-2-(2-furyl)-(1,2,4)triazolo(1,5-c)quinazolin-5-imine