Quantitative Estimation of Metaxalone in rat serum using Ultrafast Liquid Chromatography

Metaxalone is skeletal muscle relaxant used for treating skeletomuscular pains. A new and reliable liquid chromatography method was developed and validated for estimation of metaxalone in wistar rat serum. The analyte was extracted from wistar albino rat serum using diethyl ether as extraction solvent. A C-18 column (250mm×4.6mm, 5μm) using methanol: water (80: 20, % v/v) flowing at 1.0mL/min, with detection at 225nm was the optimized chromatographic condition. Metaxalone shows a retention time of 4.4min and was well resoluted from serum components as well as internal standard vilazodone (6.3min) showing method linearity at 50-3200ng/mL with acceptable accuracy and precision. The newly optimized method was validated for various parameters with values in accordance to federal guidance. The current method was found to show reliable and reproducible recovery of analyte and has the potential for application in pharmacokinetic, bioavailability and bioequivalence studies.