A radioimmunoassay for the determination of tipredane in human plasma

• Published in: Journal of pharmaceutical and biomedical analysis 1996-10, Vol.15 (1), p.21-31
• Main Authors: Bayliss, M.A.J., Preston, J.R., Wilkinson, D., Wilkinson, D.J., Lockley, W.J.S.
• Format: Article
• Language: English
• Subjects: 125I-labelled radioligand; Administration, Topical; Androstadienes - blood; Androstadienes - metabolism; Anti-Inflammatory Agents - blood; Anti-Inflammatory Agents - metabolism; Biological and medical sciences; Bones, joints and connective tissue. Antiinflammatory agents; Glucocorticoids; Humans; Immune Sera - chemistry; Medical sciences; Pharmacology. Drug treatments; Radioimmunoassay; Radioimmunoassay - methods; Tipredane
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/0731-7085(96)01816-X

A sensitive method for the determination of tipredane in human plasma has been developed. Prior to radioimmunoassay, proteins are removed from plasma by precipitation with acetonitrile. A [ 125I]iodohistamide derivative of tipredane is used as a heterogeneous radioligand. The primary antiserum is raised in sheep against a tipredane ( O-carboxymethyl) oxime-bovine serum albumin conjugate. Donkey anti-sheep IgG antiserum is used as the secondary antiserum in a double antibody separation procedure. The limit of quantification of the method is 1 ng ml −1 for 500 μl of plasma. There is no significant interference from either established or putative metabolites of tipredane, endogenous steroids or a wide range of other drugs. The assay was used to determine the concentrations of tipredane in plasma samples collected in pilot clinical studies.