A selective and accurate liquid chromatography-tandem mass spectrometry method for the quantitation of the novel 5-HT4 receptor partial agonist SUVN-D4010 (Usmarapride) in human plasma and urine.

Liquid chromatography and the tandem mass spectrometry method to quantitate SUVN-D4010 (Usmarapride) in human plasma and urine have been developed and fully validated in compliance with regulatory guidelines. The sample preparation technique is simple and rapid consisting of acetonitrile precipitation followed by dilution of supernatant with a compatible solvent. Chromatographic separation was achieved on an X-Bridge C18 (2.1×50 mm, 3.5 µm) column using 0.1% v/v ammonium hydroxide and acetonitrile as mobile phase components, delivered at a flow rate of 0.75 mL min-1. Electrospray Ionization technique in positive mode was used for mass spectrometric detection. Selective reaction monitoring (SRM) transitions of m/z 384.2 → 352.1 for SUVN-D4010 and m/z 388.2 → 356.1 for SUVN-D4010-d4 were used for quantitation. Calibration curves for SUVN-D4010 were linear across the concentration range of 0.3-300 ng mL-1 in human plasma and 5.00-5000 ng mL-1 in human urine. The method generated results with acceptable accuracy (± 9.0%), precision (%CV, ≤8.7), and mean extraction recovery (≥93.4%) with negligible matrix effect in both plasma and urine. SUVN-D4010 was found to be stable in human plasma and urine at the defined storage conditions. The validated method was successfully applied to quantitate SUVN-D4010 in human plasma and urine from a clinical first-in-human study conducted to evaluate its safety, tolerability, and pharmacokinetics in healthy adults.