Quantification of Metaxalone in Human Plasma by Liquid Chromatography Coupled to Tandem Mass Spectrometry

Abstract

A simple, rapid, sensitive, and selective liquid chromatography-tandem mass spectrometry (MS) method was developed and validated for the quantification of metaxalone, a skeletal muscle relaxant, in human plasma using galantamine as internal standard (IS). Following liquid-liquid extraction, the analytes were separated using an isocratic mobile phase on a reverse phase C18 column and analyzed by MS in the multiple reaction monitoring mode using the respective [M+H]+ ions, m/z 222/161 for metaxalone and m/z 288/213 for the IS. The assay exhibited a linear dynamic range of 50-5000 microg/L for metaxalone in human plasma. The lower limit of quantification was 50 microg/L with a relative standard deviation of less than 10%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.5 min for each sample made it possible to analyze more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability, or bioequivalence studies.

RP-HPLC Method for Determination of Metaxalone Using Box- Behnken Experimental Design.

“…Metaxalone (MTX), a 2-oxazolidinone derivative (5-(3, 5-dimethylphenoxymethyl)-2-oxazolidinone) with skeletal muscle relaxant activity [1,2] is shown in Figure 1. Analytical methods using RP-HPLC [3,4]; liquid chromatography mass spectrometry (LC-MS/MS) [5][6][7] and ultra-violet (UV) spectroscopy [8,9] has been successfully reported for MTX quantification. However, none of them adopt systematic statistical optimization; rather those methods pursued traditional approach i.e.…”

Metaxalone estimation in biological matrix using high-throughput LC–MS/MS bioanalytical method

“…Savard et al reported a tedious liquid-liquid extraction method of metaxalone using LC-MS/MS technique but complete validation data were unavailable to support method application [9]. Nirogi et al also reported liquid-liquid extraction technique to determine metaxalone in plasma by using LC-MS/MS principle, yet matrix effect using hemolyzed and lipemic plasma and stability of metaxalone in blood remained un-addressed during validation performance [10]. Moreover, there is no reported method where metaxalone recovery was achieved higher than 75% to the best of knowledge of authors.…”

New Stability-Indicating RP-HPLC Method for Determination of Diclofenac Potassium and Metaxalone from Their Combined Dosage Form

“…Some of the reported methods for DIC include UV-spectroscopic methods [3–6], RP-HPLC methods [7–10] and LC-MS method [11]. For MET the reported methods are UV-Spectroscopic method [12], RP-HPLC method [13, 14] and LC-MS method [15]. Only one RP-HPLC method has been reported so far for simultaneous estimation of both the drugs [16], but the reported method is not stability-indicating in nature.…”