Gardner JJ, Preston JR, Gilbert CM, Wilkinson DJ, Lockley WJ, Brown K. A radioimmunoassay method for the determination of nedocromil sodium in plasma and urine.
J Pharm Biomed Anal 1988;
6:285-97. [PMID:
16867419 DOI:
10.1016/0731-7085(88)80055-4]
[Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/1986] [Revised: 07/07/1986] [Indexed: 11/21/2022]
Abstract
A radioimmunoassay method for the determination of nedocromil sodium (FPL 59002 disodium salt) in human plasma and urine is described. The method employs a primary antiserum raised in a sheep, and a mono-tyramide derivative of nedocromil sodium labelled with iodine-125 as a heterogeneous radioligand. Free and bound radioligand are separated using a secondary anti-sheep IgG antiserum. All three reagents are added simultaneously to samples containing nedocromil sodium prior to an overnight incubation. The method has a limit of detection of 0.25 ng ml(-1), when plasma sample volumes of 100 microl are analysed, and is accurate and precise. Inter-assay relative standard deviations (N = 18) of 15.1, 5.0 and 5.6% were found at concentrations in plasma of 0.5, 2.0 and 6.0 ng ml(-1) respectively. The method is specific as indicated by negligible cross-reaction of the anti-nedocromil sodium antiserum with a range of drugs. The method is applicable to the analysis of samples from subjects who have inhaled nedocromil sodium from a pressurised aerosol.
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