title: Liquid chromatographic tandem mass spectrometric assay for simultaneous quantification of compound 97/78 and its in vivo metabolite 97/63, a novel trioxane antimalarial, in human plasma and its application to a protein binding study.
abstract: A sensitive, selective and specific LC-MS/ MS assay for simultaneous quantification of compound 97/78 and its active in vivo metabolite 97/63, a novel 1,2,4-trioxane antimalarial, in human plasma has been developed and validated using alpha-arteether as internal standard (IS). Extraction from plasma involves a simple protein precipitation method. The analytes were chromatographed on a Columbus C18 column with guard by isocratic elution with acetonitrile:ammonium acetate buffer (10 mM, pH 4.0) (80:20 v/v) as mobile phase at a flow rate of 0.45 mL min(-1) and analyzed in multiple reaction-monitoring (MRM) positive ion mode. The chromatographic run time was 4.0 min. The weighted (1/x2) calibration curves were linear over a range of 1.56-200 ng mL(-1) with correlation coefficients > 0.998. For both analytes, the limit of detection (LOD) and lower limit of quantification (LLOQ) were 0.5 ng mL(-1) and 1.56 ng mL(-1), respectively. The recovery of 97/78, 97/63 and IS from spiked control samples were > 90% and their matrix suppression obtained were < 8 %. The accuracy (% bias) and precision (%RSD) for both analytes were < 6.78%. Both analytes were stable after three freeze-thaw cycles (% deviation < 12.80), long-term for 30 days in plasma at -60 degrees C (% deviation < 14.38), for 8 h on bench top in plasma at ambient temperature (% deviation < 1.52) and also in the auto-sampler for 12 h (% deviation < 3.9%). The validated method was successfully applied to a protein binding study of compound 97/78 and metabolite 97/63 in human plasma. Furthermore, the validated method will be applicable to pharmacokinetics, bioavailability and metabolism in various clinical phases and in drug interaction studies.
authors: Pharmacokinetics and Metabolism Division, Central Drug Research Institute, CSIR, Lucknow, India.
authors: Hari Narayan
authors: HN
authors: Kushwaha
authors: Nagsen
authors: N
authors: Gautam
authors: Shio Kumar
authors: SK
authors: Singh
mesh_terms: D000962:Antimalarials / Q000097:blood* / Q000493:pharmacokinetics; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D005615:Freezing; D006573:Heterocyclic Compounds, 1-Ring / Q000097:blood* / Q000493:pharmacokinetics; D006801:Humans; D007202:Indicators and Reagents; D057230:Limit of Detection; D011485:Protein Binding; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D013141:Spiro Compounds / Q000097:blood* / Q000493:pharmacokinetics; D053719:Tandem Mass Spectrometry
chemical_list: C561799:97-63 compound; C557687:97-78 compound; D000962:Antimalarials; D006573:Heterocyclic Compounds, 1-Ring; D007202:Indicators and Reagents; D013141:Spiro Compounds