title: Radioimmunoassay and plasma concentrations of the anti-allergenic agent, 2-methoxy-11-oxo-11-H-pyrido[2,1-b]quinazoline-8-carboxylic acid in man.
abstract: A specific radioimmunoassay (RIA) for the determination of the antiallergenic agent, 2-methoxy-11-oxo-11H-pyrido[2,1-b]quinazoline-8-carboxylic acid (I), directly in plasma has been developed employing a rabbit antiserum to an albumin conjugate of I. The RIA has a limit of sensitivity of 0.4 ng/ml of I using a 0.1 ml sample of plasma. The intra- and interassay coefficients of variation did not exceed 6 and 9%, respectively. The specificity of the RIA was established by comparison with a less sensitive high-performance liquid chromatographic procedure and excellent agreement (r = 0.98) was observed when plasma samples were assayed by both methods. The RIA was used to determine plasma concentrations of I in man, for the first time, following oral administration of single 2, 10 and 50 mg doses of the drug.
mesh_terms: D000328:Adult; D000818:Animals; D000917:Antibody Formation; D000918:Antibody Specificity; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006967:Hypersensitivity / Q000188:drug therapy*; D008297:Male; D011725:Pyridines / Q000097:blood*; D011799:Quinazolines / Q000097:blood*; D011863:Radioimmunoassay
chemical_list: D011725:Pyridines; D011799:Quinazolines; C023625:2-methoxy-11-oxo-11H-pyrido(2,1-b)quinazoline-8-carboxylic acid