title: Simultaneous determination of dextromethorphan, dextrorphan, and guaifenesin in human plasma using semi-automated liquid/liquid extraction and gradient liquid chromatography tandem mass spectrometry.
abstract: A method for the simultaneous determination of dextromethorphan (DEX), dextrorphan (DET), and guaifenesin (GG) in human plasma was developed, validated, and applied to determine plasma concentrations of these compounds in samples from six clinical pharmacokinetic (PK) studies. Semi-automated liquid handling systems were used to perform the majority of the sample manipulation including liquid/liquid extraction (LLE) of the analytes from human plasma. Stable-isotope-labeled analogues were utilized as internal standards (ISTDs) for each analyte to facilitate accurate and precise quantification. Extracts were analyzed using gradient liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Use of semi-automated LLE with LC-MS/MS proved to be a very rugged and reliable approach for analysis of more than 6200 clinical study samples. The lower limit of quantification was validated at 0.010, 0.010, and 1.0 ng/mL of plasma for DEX, DET, and GG, respectively. Accuracy and precision of quality control (QC) samples for all three analytes met FDA Guidance criteria of +/-15% for average QC accuracy with coefficients of variation less than 15%. Data from the thorough evaluation of the method during development, validation, and application are presented to characterize selectivity, linearity, over-range sample analysis, accuracy, precision, autosampler carry-over, ruggedness, extraction efficiency, ionization suppression, and stability. Pharmacokinetic data are also provided to illustrate improvements in systemic drug and metabolite concentration-time profiles that were achieved by formulation optimization.
authors.affiliation: The Procter and Gamble Company, Health Care Research Center, 8700 Mason-Montgomery Road, Mason, OH 45040, USA.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Eichhold
authors.forename: David L
authors.initials: DL
authors.lastname: McCauley-Myers
authors.forename: Deepa A
authors.initials: DA
authors.lastname: Khambe
authors.forename: Gary A
authors.initials: GA
authors.lastname: Thompson
authors.forename: Steven H
authors.initials: SH
authors.lastname: Hoke
mesh_terms: D000284:Administration, Oral; D000996:Antitussive Agents / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D001322:Autoanalysis / Q000379:methods; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D018592:Cross-Over Studies; D003915:Dextromethorphan / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D003917:Dextrorphan / Q000097:blood* / Q000493:pharmacokinetics; D004311:Double-Blind Method; D004338:Drug Combinations; D004355:Drug Stability; D004356:Drug Storage; D005100:Expectorants / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006140:Guaifenesin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D017408:Guidelines as Topic; D006801:Humans; D016014:Linear Models; D012015:Reference Standards; D012016:Reference Values; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards
chemical_list: D000996:Antitussive Agents; D004338:Drug Combinations; D005100:Expectorants; D003917:Dextrorphan; D006140:Guaifenesin; D003915:Dextromethorphan