Simultaneous determination of theophylline, tolbutamide, mephenytoin, debrisoquin, and dapsone in human plasma using high‐speed gradient liquid chromatography/tandem mass spectrometry on a silica‐based monolithic column

Abstract

Simultaneous determination of theophylline, tolbutamide, mephenytoin, debrisoquin, and dapsone in human plasma using high-speed gradient liquid chromatography/tandem mass spectrometry on a silica-based monolithic column Theophylline, tolbutamide, mephenytoin, debrisoquin, and dapsone are marker substrates for CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, respectively. A silica-based monolithic column (Chromolith SpeedROD RP-18e, 5064.6 mm) was used to separate these five marker substrates of cytochrome P450 within only 84 s. Linear gradient elution was from acetonitrile-water-formic acid (10 : 90 : 1, v/v/v) to acetonitrile-water-formic acid (90 : 10 : 1, v/v/v) in 1.4 min. The flow rate was 2.5 mL/ min. The retention time was 0.52 min for theophylline, 0.67 min for debrisoquin, 0.78 min for dapsone, 0.96 min for mephenytoin, and 1.13 min for tolbutamide. Detection was by tandem mass spectrometry using a PE Sciex API 3000 mass spectrometer with a Turbo-Ionspray source in positive mode. A simple protein precipitation method was used. This method was validated over the concentration range of 5 -2000 ng/mL based on the sample volume of 0.1 mL.

Simultaneous determination of tolbutamide, omeprazole, midazolam and dextromethorphan in human plasma by LC–MS/MS—A high throughput approach to evaluate drug–drug interactions

“…Warfarin (administered with vitamin K, the pharmacodynamic effect is ablated) was used as a safe and accurate biomarker for CYP2C9 [19]. LC-MS/MS method was validated for theophulline, tolbutamide, mephenytoin, debrisoquin, and dapsone as probes for CYP 1A2, 2C9, 2C19, 2D6, and 3A4 [20]. Depending on the study design, therapeutic area of the drug candidate, potential co-administered medicine, and physician or clinic site's preference, several combinations of cocktails can be employed and not all probes may be included in the in vivo studies if the in vitro data suggested lack of evidence for certain probes.…”

“…Due to its speed, sensitivity, and selectivity, liquid chromatography/tandem mass spectrometry (LC-MS/MS) has become the method of choice for analyzing drug candidates in biofluids [9][10][11]. In vitro metabolic interaction screening assay for determination of marker substrates of CYP450s using N-in-1 approach and LC-MS/MS have been reported earlier [12][13][14][15].…”

Development and validation of a sensitive LC–MS/MS method for the simultaneous quantitation of theophylline and its metabolites in rat plasma

“…The use of MS has decreased detection limits to as low as 63 ng/mL for theophylline metabolites. Run times were reduced to under 10 min using LC-MS/MS methods [6][7][8][9][10][11][12][13]. However, all of these methods involved multistep extractions, large volumes of organic solvent, and required intensive labor to prepare the sample.…”

Increased productivity in quantitative bioanalysis using a monolithic column coupled with high‐flow direct‐injection liquid chromatography/tandem mass spectrometry

“…Recently, several papers4–11 have been published regarding the use of monolithic columns for high‐throughput biological sample analysis. The unique biporous structure12–14 of the monolithic column, where small mesopores provide large surface areas for sufficient separation capacity and larger through pores provide considerably reduced back‐pressure at high flow rates, allows high efficiency separation at high flow rates.…”