Simultaneous quantification of alpha-/beta-diastereomers of arteether, sulphadoxine and pyrimethamine: a promising anti-relapse antimalarial therapeutic combination, by liquid chromatography tandem mass spectrometry.
A rapid, sensitive, selective and specific HPLC/ESI-MS/MS assay method was developed and validated for the simultaneous quantitation of alpha-/beta-diastereomers of arteether (AE), sulphadoxine (SDX) and pyrimethamine (PYR) in rat blood plasma using propyl ether analogue of beta-arteether as internal standard. The method involved a single-step, liquid-liquid extraction with ethyl acetate and the analytes were chromatographed on a C18 chromatographic column by isocratic elution with methanol:ammonium acetate buffer (10 mM, pH 4) (90:10%, v/v) and analyzed by tandem mass spectrometry. The run time was 4.5 min and the weighted (1/x2) calibration curves were linear over a range of 0.78-400 ng ml-1. The method was validated fully and the lower limit of quantification (LLOQ) in plasma was 0.78 ng ml-1 for all the analytes. The intra- and inter-day precision and accuracy were found to be well within the acceptable limits (<15%) and the analytes were stable after three freeze-thaw (f-t) cycles. The absolute recoveries were consistent and reproducible. The assay method was applied to pre-clinical pharmacokinetic interaction studies of alpha-/beta-AE, SDX and PYR in rats.
Sabarinath
S
S
Pharmacokinetics and Metabolism Division, Central Drug Research Institute, Lucknow 226001, India. sn_sabari@yahoo.com
Singh
R P
RP
Gupta
R C
RC
D000818:Animals; D000962:Antimalarials / Q000032:analysis* / Q000493:pharmacokinetics; D037621:Artemisinins / Q000032:analysis* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008288:Malaria / Q000473:pathology; D008297:Male; D011739:Pyrimethamine / Q000032:analysis* / Q000493:pharmacokinetics; D051381:Rats; D012015:Reference Standards; D055502:Secondary Prevention; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D013413:Sulfadoxine / Q000032:analysis* / Q000493:pharmacokinetics
D000962:Antimalarials; D037621:Artemisinins; D013413:Sulfadoxine; C055141:artemotil; D011739:Pyrimethamine