Rizk, Mohammed SalemSultan, MahaMohamed, DaliaTony, Rehab Moussa2021-07-112021-07-1107/06/2021https://doi.org/10.1016/j.jchromb.2021.122816https://qrgo.page.link/SR9kgA simple, sensitive, rapid and specific method based on ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) for the simultaneous quantification of dantrolene (DAN) and paracetamol (PAR) in real human plasma was developed and validated. The preparation of sample was achieved by liquid–liquid extraction with tertiary butyl methyl ether. The analysis was performed on a reversed-phase C18column (1.7 µm, 2.1 × 30 mm) using acetonitrile: 0.1% formic acid (80:20, v/v) as the mobile phase and pumped in an isocratic mode at a flow rate of 0.3 mL/min using citalopram (CIT) as an internal standard. Tandem mass spectrometric detection was carried out by both positive and negative electrospray ionization (ESI) in the multiple-reaction monitoring mode (MRM). The analysis was carried out within 1 min for each sample which made it possible to analyze more than 350 human samples per day. Validation of the method was performed according to FDA guidelines for bio-analytical method. The method was found to be linear in the range of 25 – 2500 ng/mL and 100 – 10000 ng/mL for DAN and PAR, respectively. The method was applied successfully for the determination of the two analytes in the plasma after oral administration of Dantrelax® compound capsules to healthy volunteers. The study was accomplished after approval of the ethics committeeen-USUPLC–MS/MS Egyptian healthy volunteersParacetamol.Dantrolene.Dantrelax® compound capsules.Bioanalytical method validationArticlehttps://doi.org/10.1016/j.jchromb.2021.122816