A validated UHPLC-MS/MS method for simultaneous determination of lumiracoxib and its hydroxylation and acyl glucuronidation metabolites in rat plasma: Application to a pharmacokinetic study

Lumiracoxib is a selective cyclooxygenase-2 (COX-2) inhibitor. The aim of this study was to develop a simple and sensitive ultra-high performance liquid chromatography tandem mass spectrometric method (UHPLC-MS/MS) for the simultaneous determination of lumiracoxib and its circulating metabolites 4'- Hydroxyl-lumiracoxib and lumiracoxib-acyl-glucuronide in rat plasma. The analytes and diclofenac (internal standard, IS) were extracted using acetonitrile containing 0.2 % formic acid. Chromatographic separation was executed on ACQUITY BEH C-18 column (2.1 x 50 mm, 1.7 mu m) with water containing 0.2 % formic acid and acetonitrile as mobile phase. Mass detection was achieved in positive multiple reactions monitoring (MRM) mode, with precursor-to-product transitions at m/z 294.1 > 248.1, m/z 310.1 > 264.1, m/z 470.1 > 276.1 and m/z 296.0 > 250.0 for lumiracoxib, 4'-hydroxyl-lumiracoxib, lumiracoxib-acyl-glucuronide and for IS, respectively. The developed LC-MS/MS method was validated based on the guidance of U.S. Food and Drug Administration. The linearity was evident (r > 0.995) over the concentration ranges of 1-1000 ng/mL for lumiracoxib, 1-500 ng/mL for 4'-hydroxyl-lumiracoxib and 1-200 ng/mL for lumiracoxib-acyl-glucuronide, respectively. The precision (RSD) did not exceed 8.23 % and accuracy (RE) ranged from -7.85 % to 9.50 %. The extraction recovery was more than 80.54 %. All the analytes were demonstrated to be stable under the tested storage and processing conditions. The validated LC-MS/MS method has been successfully applied to the pharmacokinetic study of lumiracoxib and its metabolites in the rats after orally administered with lumiracoxib. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel UHPLC-MS/MS method was developed for the simultaneous determination of Lumiracoxib and its metabolites in rat plasma, validated according to FDA guidance, demonstrating high linearity, stability, and accuracy, suitable for pharmacokinetic studies in rats.