Bilastine: Quantitative determination by LC with fluorescence detection and structural elucidation of the degradation products using HRMS

Background: A liquid chromatography (LC) stability-indicating method was developed and validated for the quantitative determination of bilastine in coated tablets. Objective: The procedure was validated for specificity, linearity, robustness, precision, and accuracy. Plackett-Burmann experimental design was used to determine the robustness of the method. Method: Chromatographic separation was performed on a Shim-packVR RP-18 column with fluorescence detection. The degradation products formed under oxidative conditions were isolated and identified using high-resolution mass spectrometry (HRMS). In silico prediction of degradation products and in silico toxicity studies were also performed. Results: The LC method presented good recovery and precision (intraday and interday), the response was linear in a range of 0.20 to 0.70 lg mL-1, and the results demonstrated the robustness of the analytical method under the evaluated conditions. Conclusions: The degradation products were identified as benzimidazole (DP1) and amine N-oxide of bilastine (DP2). The results for the toxicity studies demonstrated the high mutagenic potential of DP1 and hepatotoxicity and hERG I inhibitor effects of DP2. Highlights: Bilastine degradation products were identified as benzimidazole and amine N-oxide using HRMS. © AOAC INTERNATIONAL 2020. All rights reserved.