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-pack® 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 µg 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.

Protective role of Syzygium cumini leaf extracts against paraquat-induced oxidative stress in superoxide-dismutase-deficient Saccharomyces cerevisiae strains

The aim of this study was to evaluate the protective effect of three different extracts prepared from Syzygium cumini leaves against paraquat-induced toxicity in Saccharomyces cerevisiaestrains deficient in superoxide dismutase (SOD). Additionally, the extracts phenolic and flavonoid contents, in vitro antioxidant activity, and phytochemical composition (using high-pressure liquid chromatography) were determined. Bioactive compounds from S. cumini leaves were extracted with infusion (traditional method) or ultrasound (aqueous or hydroalcoholic). Compared to the infusion extract, the ultrasound extracts exhibited a greater protective capacity against paraquat toxicity in the yeast cells as well as higher antioxidant activity. These results may be directly related to the higher phenolic and flavonoid contents in these extracts, since they are recognized as having high antioxidant actions.