title: Enzyme immunoassay for nomegestrol acetate in human plasma.
abstract: Currently available chromatographic assays of the progestative drug nomegestrol acetate in human plasma are not suitable for monitoring drug kinetics more than 24 h after clinical dosage. A specific and sensitive enzyme immunoassay was therefore developed. A 3(O-carboxymethyl)oxime derivative of nomegestrol acetate was synthesized and coupled to bovine serum albumin in order to raise polyclonal antibodies in rabbits. The enzymatic tracer was obtained by coupling the 3(O-carboxymethyl)oxime derivative to acetylcholinesterase (E.C.3.1.1.7.). HPLC fractionation of human plasma samples followed by enzyme immunoassay revealed the presence of cross-reacting metabolites. An automated procedure of metabolite separation was developed using silica bonded with diol groups (Diol Bakerbond column). This procedure ensured assay specificity. The quantification limit in human plasma was 0.1 ng/ml. Mean repeatability (intra-assay variation) and reproducibility (inter-assay variation) were 9 and 15%, respectively. The enzyme immunoassay allowed monitoring of the kinetics of nomegestrol acetate 144 h after oral administration of a single 5 mg dose. Values for human samples were in excellent agreement with those assayable by HPLC followed by u.v. detection.
authors.affiliation: Service de Pharmacologie et d'Immunologie, Commissariat à l'Energie Atomique, Gif-sur-Yvette, France.
authors.forename: E
authors.initials: E
authors.lastname: Ezan
authors.forename: H
authors.initials: H
authors.lastname: Benech
authors.forename: R
authors.initials: R
authors.lastname: Bucourt
authors.forename: T
authors.initials: T
authors.lastname: Ardouin
authors.forename: C
authors.initials: C
authors.lastname: Tchernatinsky
authors.forename: J L
authors.initials: JL
authors.lastname: Thomas
authors.forename: J
authors.initials: J
authors.lastname: Paris
authors.forename: J M
authors.initials: JM
authors.lastname: Grognet
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008535:Megestrol / Q000031:analogs & derivatives* / Q000097:blood / Q000276:immunology / Q000493:pharmacokinetics; D008657:Metabolic Clearance Rate; D045167:Progesterone Congeners / Q000097:blood / Q000276:immunology / Q000493:pharmacokinetics
chemical_list: D045167:Progesterone Congeners; C047637:nomegestrol; D008535:Megestrol