Development of a sensitive radioreceptor assay for oxyphenonium in plasma and urine

K. Ensing*, F. Kluivingh, T. K. Gerding, R. A. de Zeeuw

*Corresponding author for this work

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    A radioreceptor assay (RRA) for oxyphenonium has been developed. It is based on competition between [3H]dexetimide and oxyphenonium for binding to muscarinic receptors from calf striata. The RRA is optimized towards incubation medium and to extraction by ion pair formation with sodium picrate. At least 4 times 10−10 m of oxyphenonium is necessary to permit a reliable assay. This corresponds to a detection limit of drug of 2 ng ml−1 urine. After extraction, drug at 100 pg ml−1 of plasma can be estimated using 4 ml samples. The method is applicable to monitoring the drug and to the determination of its pharmacokinetics after therapeutic dosing. Urine levels can also be monitored.
    Original languageEnglish
    Pages (from-to)235-239
    Number of pages5
    JournalJournal of Pharmacy and Pharmacology
    Issue number4
    Publication statusPublished - 1984

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