Determination of Rosuvastatin and its Metabolite N-Desmethyl Rosuvastatin in Human Plasma by Liquid Chromatography–High Resolution Mass Spectrometry: Method Development, Validation, and Application to Pharmacokinetic Study

A novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for the determination of rosuvastatin (rosuva) and its metabolite N-desmethyl rosuvastatin (NDM-rosuva) in human plasma using atorvastatin as internal standard. The method was validated according to international guidelines. The analytical column used was HiChrom® C18 (150 × 3.0 mm, 3 µm; Reading, UK) and the mobile phase comprised of 0.1% formic acid in acetonitrile and 0.1% formic acid in water (70:30 v/v), pumped at 300 µL/min. The precipitation of plasma proteins and extraction of analytes were carried out by a simple one-step procedure using acetonitrile. The calibration curves were linear (r2 = 0.999) over the concentration range of 0.2–20 ng/mL for rosuva and 0.1–10 ng/mL for NDM-rosuva. The lower limits of detection and quantification for rosuva were 0.1 and 0.2 ng/mL, whereas for NDM-rosuva, these were 0.03 and 0.1 ng/mL, respectively. The intra- and inter-day precisions expressed as relative standard deviation...