A validated LC-MS/MS method for the rapid quantification of vilazodone in rat plasma: application to a pharmacokinetic study.

A rapid and sensitive LC-MS/MS method was developed for the quantification of vilazodone in rat plasma using escitalopram as internal standard. After extracted with organic solvent, post-treatment samples were chromatographed on an Agela C18 column. An isocratic mobile phase of acetonitrile: 5mM ammonium acetate: formic acid (35:65:0.1, v/v/v) was applied at a flow rate of 0.25mL/min. Detection was performed using multiple reaction-monitoring (MRM) modes at m/z 442.4→155.3 for vilazodone and m/z 325.1→109.0 for escitalopram. The method was linear in the concentration range of 1.0-100ng/mL with a correlation coefficient ≥0.993. The intra- and inter-assay precision (%RSD) values were within 13.4%, and intra- and inter-day accuracy (%RE) ranged from -9.8 to 6.9%. The total analysis time was 2.2min. The LC-MS/MS method was fully validated for its sensitivity, selectivity, stability, matrix effect and recovery. The data indicated that the developed method was rapid, specific and sensitive. This method was further and successfully applied in the pharmacokinetics study of vilazodone in rat.