title: Liquid chromatographic tandem mass spectrometric assay for quantification of 97/78 and its metabolite 97/63: a promising trioxane antimalarial in monkey plasma.
abstract: The present manuscript describes development and validation of LC-MS/MS assay for the simultaneous quantitation of 97/78 and its active in-vivo metabolite 97/63 in monkey plasma using alpha-arteether as internal standard (IS). The method involves a single step protein precipitation using acetonitrile as extraction method. The analytes were separated on a Columbus C(18) (50 mm x 2 mm i.d., 5 microm particle size) column by isocratic elution with acetonitrile:ammonium acetate buffer (pH 4, 10 mM) (80:20 v/v) at a flow rate of 0.45 mL/min, and analyzed by mass spectrometry in multiple reaction-monitoring (MRM) positive ion mode. The chromatographic run time was 4.0 min and the weighted (1/x(2)) calibration curves were linear over a range of 1.56-200 ng/mL. The method was linear for both the analytes with correlation coefficients >0.995. The intra-day and inter-day accuracy (% bias) and precisions (% RSD) of the assay were less than 6.27%. Both analytes were stable after three freeze-thaw cycles (% deviation <8.2) and also for 30 days in plasma (% deviation <6.7). The absolute recoveries of 97/78, 97/63 and internal standard (IS), from spiked plasma samples were >90%. The validated assay method, described here, was successfully applied to the pharmacokinetic study of 97/78 and its active in-vivo metabolite 97/63 in Rhesus monkeys.
authors.affiliation: Pharmacokinetics and Metabolism Division, Central Drug Research Institute, Lucknow, India.
authors.forename: R P
authors.initials: RP
authors.lastname: Singh
authors.forename: S
authors.initials: S
authors.lastname: Sabarinath
authors.forename: N
authors.initials: N
authors.lastname: Gautam
authors.forename: R C
authors.initials: RC
authors.lastname: Gupta
authors.forename: S K
authors.initials: SK
authors.lastname: Singh
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000097:blood* / Q000378:metabolism* / Q000493:pharmacokinetics; D037621:Artemisinins / Q000097:blood* / Q000378:metabolism* / Q000493:pharmacokinetics; D002853:Chromatography, Liquid / Q000379:methods*; D004195:Disease Models, Animal; D006801:Humans; D008253:Macaca mulatta; D008288:Malaria / Q000188:drug therapy*; D008297:Male; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000962:Antimalarials; D037621:Artemisinins; C031327:artemisinin