Determination of a Selective GABA-A α_2,3 Partial Agonist in Human Plasma by High Performance Liquid Chromatography with Tandem Mass Spectrometric Detection

Abstract

An automated solid phase extraction, utilizing a 96‐well plate format, was used to isolate a selective GABA‐A α_2,3 partial agonist (I) and internal standard (II) from human plasma. Following the isolation procedure, the analyte and internal standard were separated and detected using reversed phase HPLC coupled with atmospheric pressure chemical ionization (APCI) mass spectrometry operated in the positive ionization mode. Based upon the peak area ratio (analyte:internal standard), the analyte was quantified over a concentration range of 0.1 to 50 ng/mL. The absolute and relative matrix effects from different sources of human plasma on the ionization efficiency were examined and the absence of these effects was confirmed. Assay validation results including parameters such as intra‐ and inter‐day precision and accuracy are presented. The validated method was subsequently used to support human pharmacokinetic studies.

Keywords:

• GABA‐A
• Plasma
• Agonist
• HPLC
• Tandem mass spectrometry