A simple, rapid and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) assay for the determination of simvastatin in human plasma using lovastatin as internal standard (IS) was established. After being extracted by methyl tert-butyl ether, solutes were separated on a C18 column with a mobile phase consisting of methanol-water-5M ammonium acetate (90:10:0.1, v/v/v). The quantification of target compounds was carried out by using multiple reaction monitoring (MRM) mode: m/z 419.2 ? 199.1 and 405.1 ? 285.1 for simvastatin and IS, respectively. The method had a run time of 3.3 min and a linear calibration curve in the range of 0.1-20 ng/ml. The lower limit of quantification (LOQ) was about 0.1 ng/ml. The mean extraction recovery of simvastatin was over 92.48%. Intra- and inter-day variability values were less than 10.5% and 9.30%, respectively. This method offered good precision and accuracy and was successfully applied for a bioequivalence studies of 20 mg of simvastatin orally disintegrating tablets in 20 Chinese healthy volunteers.
Loading....