Validated Method for the Quantification of Baclofen in Human Plasma Using Solid-Phase Extraction and Liquid Chromatography–Tandem Mass Spectrometry

Abstract

A highly sensitive and fully validated method was developed for the quantification of baclofen in human plasma. After adjusting the pH of the plasma samples using a phosphate buffer solution (pH 4), baclofen was purified using mixed mode (C8/cation exchange) solid-phase extraction (SPE) cartridges. Endogenous water-soluble compounds and lipids were removed from the cartridges before the samples were eluted and concentrated. The samples were analyzed using triple-quadrupole liquid chromatography-tandem mass spectrometry (LC-MS-MS) with triggered dynamic multiple reaction monitoring mode for simultaneous quantification and confirmation. The assay was linear from 25 to 1,000 ng/mL (r(2) > 0.999; n = 6). Intraday (n = 6) and interday (n = 15) imprecisions (% relative standard deviation) were <5%, and the average recovery was 30%. The limit of detection of the method was 5 ng/mL, and the limit of quantification was 25 ng/mL. Plasma samples from healthy male volunteers (n = 9, median age: 22) given two single oral doses of baclofen (10 and 60 mg) on nonconsecutive days were analyzed to demonstrate method applicability.

Liquid chromatography high resolution mass spectrometry for the determination of baclofen and its metabolites in plasma: Application to therapeutic drug monitoring

“…So far some analytical methods for determination of baclofen in human plasma have been developed in liquid chromatography mass spectrometry (Flärdh & Jacobson, ; Goda et al, ; Kim et al, ; Miksa & Poppenga, ; Nahar et al, ). However, most of the already reported methods in biological matrix only allowed baclofen determination, were time consuming and required multiple and expensive sample preparation steps (Flärdh & Jacobson, ; Nahar et al, ; Sanchez‐Ponce et al, ). The described LC‐HR‐MS method is the first developed method published in the literature with all the advantages of high resolution to quantify baclofen in human plasma for applications in clinical pharmacology and toxicology.…”

“…In the literature, several studies have described the determination of baclofen in biological fluids by various methods such as capillary electrophoresis, gas chromatography and liquid chromatography with UV, fluorescence after derivatization or tandem mass spectrometry (Cao & Li, ; Desiderio et al, ; Flärdh & Jacobson, ; Goda, Murayama, Fujimaki, & Sudo, ; Kim et al, ; Millerioux, Brault, Gualano, & Mignot, ; Nahar et al, ). All of the methods described have been validated only for the quantification of baclofen in different biological matrices and require complex sample preparation procedures such as derivatization, liquid–liquid extraction, solid‐phase extraction or ion pair extraction.…”

LCMS/MS assay for baclofen, a derivative of γ –aminobutyric acid (GABA) in human plasma and its clinical application

“…Kromasil, 100-5C8, 4.6×150 mm gave a sensible peak shape and response even at LLOQ quantity the analyte at retention time of 1.85 ± 0.3min.The flow rate of 0.8 mL/min allowed a runtime to 3.0 min. Reported methods were used SPE 3, 5 and PP 4 to extract baclofen from human plasma samples. For LC-MS analysis, there should be a proper extraction procedure which can yields good recovery with no or minimal matrix effect.…”

“…But the run time was 12 min, which is very high for high throughput bioanalysis of baclofen. The another author Nahar et al,2016 5 quantified baclofen in plasma samples using solid phase extraction technique in the linearity range of 25-1000 ng/mL. However, the run was >5 min, which is not suitable for routine bioanalytical application.…”

Simultaneous Quantitation of S(+)- and R(−)-Baclofen and Its Metabolite in Human Plasma and Cerebrospinal Fluid using LC–APCI–MS/MS: An Application for Clinical Studies

“…Baclofen has been determined in a variety of different biological matrices using analytical techniques based on gas chromatography [19,20], liquid chromatography-mass spectrometry (LC-MS) [21,22], as well as electrophoresis [23]. However, the methods mentioned above require complex procedures to prepare samples, including using solid phase extraction (SPE).…”