UPLC-MS/MS assay for identification and quantification of brivaracetam in plasma sample: Application to pharmacokinetic study in rats.

Brivaracetam (BVR) is a novel antiepileptic drug (AED), approved clinically for the treatment of partial onset seizures in adults and adolescents. It has some abuse potential and assigned to Schedule V category under the Controlled Substance Act by the Drug Enforcement Administration. Being an AED and drug of abuse, a sensitive and robust assay is necessary for determination of BVR in biological fluids. Herein, we report a sensitive and validated UPLC-MS/MS assay for identification and quantification of BVR in plasma samples. The samples were prepared by one step liquid liquid extraction method using tert-Butyl methyl ether as extracting solvent. BVR and internal standard (carbamazepine) were separated on Aquity BEH™ C-18 column and eluted by using gradient mobile phase combination of acetonitrile and 0.1% formic acid in water. The precursor to product ion transition of m/z 213.12→54.95 (qualifier), 213.12→168.10 (quantifier) for BVR, and m/z 237.06→193.25 for IS were used for MRM detection and quantification. The assay was validated according to USFDA and SWGTOX guidelines for method validation and all parameter results were within the acceptable limits. The calibration curves were found to be linear in concentration range of 1.98-2000ng/mL (r2≥0.995) having LOD and LLOQ of 0.80 and 1.98ng/mL, respectively. The assay was successfully employed in BVR pharmacokinetic study in rats and can be suitable for therapeutic drug monitoring, pharmacokinetic study and forensic analysis.