Quantitative determination of antalarmin, a novel corticotropin-releasing hormone receptor-1 antagonist, in canine plasma by HPLC-MS

✍ Scribed by Stephen D. Fox; John M. Roman; Giovanni Cizza; Timothy D. Veenstra; Haleem J. Issaq

• Book ID: 102924490
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 656 KB
• Volume: 28
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/jssc.200400048

✦ Synopsis

Abstract

A simple and rapid method was developed for the quantitation of antalarmin from plasma using high performance liquid chromatography coupled with electrospray ionization mass spectrometry (ESI/MS). Separation of antalarmin from interfering compounds was achieved using reversed phase chromatography on a C‐8 micro‐column with an isocratic mobile phase comprised of 80% acetonitrile, 20% water, and 5 mM triethylamine. Detection by ESI/MS was accomplished in positive ion mode using single ion monitoring of the protonated molecular ions of antalarmin and its ^13^C~2~‐isotopimer. The area ratio of the integrated peaks of interest in the extracted ion chromatogram was used for quantitation. The lower limit of detection was 1 picogram (pg) and the quantitation showed a linear response up to 4 nanograms loaded on column. To achieve acceptable accuracy at or around the limit of quantitation of 20 pg, a 1/x weighting was applied to the calibration data. Accuracy and precision variation for intra and inter‐day validation were below the acceptable limit (15%) for pharmacokinetic studies.