Abstract
Two separate analytical methods have been developed for the determination of butorphanol and its metabolites in human plasma. One method is specific for butorphanol (I) while the other determines the metabolites, hydroxybutorphanol (II) and norbutorphanol (III). Both procedures incorporate solid-phase extraction, chemical derivatization and separation, and detection using gas chromatography-electron-capture negative-ion chemical ionization mass spectrometry (GC-ECNCI-MS). Both methods use the cyclopropyl analog of I (BC-2605, IV) as the internal standard and the procedures for extraction of the analytes from plasma are identical. However, following extraction, either the pentafluorobenzoyl ester of I or the tris- and bis-trifluoroacetyl esters of II and III, respectively, were prepared. The derivatives were analyzed by GC-ECNCI-MS with selected-ion monitoring of the molecular ions. The standard curves were linear over the concentration ranges of 20–2000, 20–1000 and 50–1000 pg/ml for I, II and III, respectively. All standard curves from the assay validation had r 2 values of ≥0.994, 0.991 and 0.985 for I, II and III, respectively. For all three compounds, the intra- and inter-assay precisions (CV) and inter-assay accuracy (deviation from nominal) were within 12% for plasma quality control samples. All derivatives were stable in the reconstitution solvent for at least 24 h. The assays are being used for the determination of plasma concentrations of I, II and III in humans following repeated administration of nasal spray.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Journal of Chromatography B: Biomedical Sciences and Applications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.