Determination of the cardioactive prototype LASSBio-294 and its metabolites in dog plasma by LC–MS/MS: Application for a pharmacokinetic study

In this work we describe the evaluation of the pharmacokinetics of a novel cardioactive compound of the N-acylhydrazone class, LASSBio-294, using high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) in dog plasma for the first time. Separation was achieved on a ZORBAX Rapid Resolution High Definition (RRHD) SB-C18 (50 mm × 2.1 mm, 1.8 μm) reversed-phase column at 20 °C with methanol-10 mM ammonium acetate solution (65:35, v/v) at a flow rate of 1.0 mL/min. Detection was performed using an electrospray ionization (ESI) operating in positive ion multiple reaction monitoring (MRM) mode by monitoring the ion transitions from m/z 275.2 → 149.1 (LASSBio-294) and m/z 152.0 → 110.0 (acetaminophen, internal standard). The calibration curve of LASSBio-294 in plasma showed good linearity over the concentration range of 1.25–800 ng/mL. The validated method was successfully applied to a pre-clinical pharmacokinetic study of the cardioactive prototype LASSBio-294 in beagles after oral administration. The main pharmacokinetic parameters t1/2, Cmax and AUC0–24 were (5.74 ± 0.55) h, (547.66 ± 35.12) ng/mL and (1621.77 ± 41.66) ng h/mL, respectively.