title: Simultaneous Determination of Tramadol and its Metabolite in Human Plasma by GC/MS.
abstract: A simple and sensitive GC/MS method for the determination of tramadol and its metabolite (O-desmethyltramadol) in human plasma was developed and validated. Medazepam was used as an internal standard. The calibration curves were linear (r=0.999) over tramadol and O-desmethyltramadol concentrations ranging from 10 to 200 ng/mL and 7.5 to 300 ng/mL, respectively. The method had an accuracy of >95% and intra- and interday precision (RSD%) of ≤4.83% and ≤4.68% for tramadol and O-desmethyltramadol, respectively. The extraction recoveries were 97.6±1.21% and 96.3±1.66% for tramadol and O-desmethyltramadol, respectively. The LOQ using 0.5 mL human plasma was 10 ng/mL for tramadol and 7.5 ng/mL for O-desmethyltramadol. Stability studies showed that tramadol and O-desmethyltramadol were stable in human plasma after 8 h incubation at room temperature or after 1 week storage at -20°C with three freeze-thaw cycles. Also, this method was successfully applied to six patients who had been given an intravenous formulation of 100 mg tramadol with Cmax results of 2018.1±687.8 and 96.1±22.7 ng/mL for tramadol and O-desmethyltramadol, respectively.
authors: Ataturk University, Faculty of Pharmacy, Department of Analytical Chemistry, 25240, Erzurum, Turkey.
authors: Bılal
authors: B
authors: Yılmaz
authors: Alı Fuat
authors: AF
authors: Erdem
mesh_terms: D000701:Analgesics, Opioid / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D019540:Area Under Curve; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008472:Medazepam / Q000097:blood / Q000737:chemistry; D015394:Molecular Structure; D015203:Reproducibility of Results; D014147:Tramadol / Q000031:analogs & derivatives* / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D000701:Analgesics, Opioid; C080580:O-demethyltramadol; D014147:Tramadol; D008472:Medazepam