title: Development of a sensitive UPLC-ESI-MS/MS method for quantification of sofosbuvir and its metabolite, GS-331007, in human plasma: Application to a bioequivalence study.
abstract: A rapid and simple LC-MS/MS method was developed and validated for the simultaneous estimation of sofosbuvir (SF) and its metabolite GS-331007 (GS) using famotidine as an internal standard (IS). The Xevo TQD LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. Extraction with ethyl acetate was used in sample preparation. The prepared samples were chromatographed on Acquity UPLC HSS C₁₈ (50 mm × 2.1 mm, 1.8 μm) column by pumping 0.1% formic acid and acetonitrile (50:50, v/v) in an isocratic mode at a flow rate of 0.3 ml/min. Method validation was performed as per the FDA guidelines and the standard curves were found to be linear in the range of 10-2500 ng/ml for both SF and its metabolite. The intra-day and inter-day precision and accuracy results were within the acceptable limits. A very short run time of 1.2 min made it possible to analyze more than 300 human plasma samples per day. The developed assay method was successfully applied to a bioequivalence study in human volunteers.
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt. Electronic address: mamdouh.rezk@pharma.cu.edu.eg.
authors.forename: Mamdouh R
authors.initials: MR
authors.lastname: Rezk
authors.affiliation: Pharmaceutics and Industrial Pharmacy Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt.
authors.forename: Emad B
authors.initials: EB
authors.lastname: Basalious
authors.affiliation: Advanced Research Center (ARC), Nasr City, Cairo, Egypt.
authors.forename: Iman A
authors.initials: IA
authors.lastname: Karim
mesh_terms: D019540:Area Under Curve; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004355:Drug Stability; D064368:Healthy Volunteers; D006801:Humans; D057230:Limit of Detection; D010949:Plasma / Q000378:metabolism*; D011786:Quality Control; D015203:Reproducibility of Results; D000069474:Sofosbuvir / Q000097:blood* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014529:Uridine / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry
chemical_list: C000608248:GS331007; D014529:Uridine; D000069474:Sofosbuvir
keywords: Bioequivalence; GS-331007; Plasma; Sofosbuvir; UPLC-MS/MS; Validation