A sensitive LC-MS/MS assay for the determination of dextromethorphan and metabolites in human urine—application for drug interaction studies assessing potential CYP3A and CYP2D6 inhibition

Response normalized liquid chromatography nanospray ionization mass spectrometry

“…14 C-DL [8-chloro-6, 11-dihydro-11-(4-piperidylidene)-5H-benzo [5,6] cyclohepta [1,2-b]pyridine, 14 C-SCH 34117] was synthesized at Schering-Plough Research Institute (Kenilworth, NJ) and had Ͼ99% radiochemical purity. As described elsewhere [42,43], monkeys (n ϭ 3) were administered a single oral dose in 0.4% aqueous methylcellulose by gavage at a targeted dose level of 6.5 mg […”

“…LC-MS/MS techniques for quantitation require reference and internal standard(s), so that LC-MS/MS responses from unknown quantities of relevant drug-related peaks can be related back to responses obtained using known quantities of each analyte. Usually a standard curve is generated for each and every analyte to be quantified [6]. Although reference standards may be available for the parent drug, it is very unlikely to have standards for metabolites available in early stage of drug discovery and development thereby making conventional LC-MS/MS based quantitation of metabolites impractical.…”

“…The widely different LC-MS responses observed for compounds with structural changes, such as those resulting from metabolism, however, limits the use of LC-MS in full scan detection mode for quantitative determination of drugs and/or metabolites. LC-MS/MS based assays involving selected reaction monitoring (SRM) or multiple reaction monitoring (MRM) techniques are routinely used for quantitative determination of drugs and/or metabolites in biological matrices [1][2][3][4][5][6][7]. LC-MS/MS techniques for quantitation require reference and internal standard(s), so that LC-MS/MS responses from unknown quantities of relevant drug-related peaks can be related back to responses obtained using known quantities of each analyte.…”

Sensitive and Selective Reversed-Phase High Performance Liquid Chromatographic-UV Spectrophotometric Determination of Dextromethorphan and its CYP2D6 Mediated Metabolite, Dextrorphan in Human Urine

“…Additionally, the sample preparation procedures described in these methods generally suffered from low analyte recoveries. Again, the assay selectivity in the presence of other metabolites was not mentioned and the selectivity of the method in urine samples originating from different subjects was not evaluated [17]. All these may adversely affect the determination of DMP, DP and other metabolites.…”

A validated SIM GC/MS method for the simultaneous determination of dextromethorphan and its metabolites dextrorphan, 3‐methoxymorphinan and 3‐hydroxymorphinan in biological matrices and its application to in vitro CYP2D6 and CYP3A4 inhibition study

“…Various analytical methods for the determination of dextromethorphan and/or its metabolites in biological matrices have been reported, such as high-performance liquid chromatography combined with fluorescence detection (East and Dye, 1985;Johansson and Svensson, 1988;Chen et al, 1990;Lam and Rodriquez, 1993;Hartter et al, 1996;Bartoletti et al, 1996;Kimiskidis et al, 1996;Bendriss et al, 2001;Hendrickson et al, 2003;Afhsar et al, 2004;Lin et al, 2007) or ultraviolet detection (Park et al, 1984;Vielnascher et al, 1996), capillary electrophoresis (Kristensen, 1998), gas chromatography coupled with different detectors (Pfaff et al, 1983;Bauman and Jonzier-Perey 1988;Wu et al, 2003;Bagheri et al, 2005;Rodriques et al, 2008) and liquid chromatography-mass spectrometry (Vengurlekar et al, 2002;Arellano et al, 2005;Constanzer et al, 2005). GC/MS in the SIM mode and LC-MS/MS are the preferred methods in terms of sensitivity and selectivity.…”