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.
Maca (Lepidium meyenii Walp.) has been used in folk medicine to treat fertility disturbances, a claim that has been evidenced in some studies. However, the clinical trials validating this use have shown paradoxical findings and then maca safety is not well known. This study investigated the effects and mechanisms by which maca affects the reproductive system using an in vivo model, the nematode Caenorhabditis elegans. Tuber maca powder, obtained from local commerce, was used to prepare the aqueous extract. Worms were acutely exposed to maca extracts (40, 120, 240, and 330 μg/μl), and 48 h after treatments, physiological and biochemical assays were conducted. Maca extract caused a significant decrease in total number of eggs and in the number of eggs per worm. These effects were associated to increased lipid peroxidation, reduced triacylglycerol levels, and also impaired vit‐2 (vitellogenin) expression, besides increase in the number of apoptotic germline cells. We have found quantifiable levels of alkaloids in this maca extract, which presence could be related to this toxicity. Collectively, our data suggest that maca extract exposure causes reproductive toxicity to worms that could be, at least in part, associated to both an increase in apoptosis of germline cells and also to a decrease in vitellogenin expression, needed for egg yolk production and, consequently, successful reproduction.
A principal novidade das eleições presidenciais de 2018 no Brasil foi o movimento Mulheres unidas contra Bolsonaro, tendo aglutinado em torno da consigna #EleNão diversos setores organizados da luta feminista e milhões de mulheres sem filiação alguma, inclusive sem experiência de prática política. O Movimento que nasceu nas redes sociais acumulou força e agregou mulheres de forma tão expressiva que viabilizou sua presença nas ruas e demonstrou-se capaz de realizar a difícil tarefa de agregar setores políticos que têm sido incapazes de cooperar entre si e de construir uma frente de luta ampla, unificada e, ao mesmo tempo, plural. Através de análise qualitativa, pretendemos identificar a natureza do movimento Mulheres unidas contra Bolsonaro e compreender por que foram as mulheres o principal grupo social a mobilizar-se contra o candidato do PSL.
A new stability-indicating liquid chromatography method was developed for the quantification of empagliflozin and two synthetic impurities. The chromatographic conditions included Spherisorb® RP-18 column (150 × 4.6 mm, 5 μm) with a PDA detector, using acetonitrile and formic acid (pH 4.0) as mobile phase in gradient elution and flow-rate of 1.2 mL·min−1. The gradient increasing from 51 to 100% acetonitrile until 11.00 min, followed by decreasing the solvent from 100% to the initial ratio from 11.01 to 15.00 min. The method was validated according to International Council of Harmonization guidelines. The LOD and LOQ values for impurities A and B were 35 and 15 ng·mL−1, respectively, (for LOD) and 115 and 35 ng.mL−1, respectively (for LOQ). The method was linear in the range of 80–140, 115–1150 and 35–350 ng·mL−1 for EMPA, impurities A and B, respectively, and the correlation coefficient were > 0.999 in all situations, indicating the method good linearity. The developed method showed a good recovery for empagliflozin and added impurities. The method has proven to be precise, demonstrated values less than 2.0% to empagliflozin and 5.0% to synthetic impurities, robust and selective with no interference from other products in the determination of analytes. The in silico toxicity prediction suggested that the impurities do not present any toxicity risk for the parameters evaluated.
Aim: A new stability-indicating liquid chromatography method was developed and validated for the quantitative determination of luliconazole. Materials and methods: Preliminary forced degradation study demonstrated an additional peak of the degradation product at the same retention time to the drug, due to this, the method was developed optimizing the chromatographic conditions to provide sufficient peak resolution (R ≥ 2). The experimental design was evaluated to assess the robustness and the best chromatographic conditions to be used for the validation. Methodology: Luliconazole solutions were exposed to various stress conditions to evaluate the method indication stability, in which the degradation product (DP-1) formed was isolated, identified, and evaluated in silico to predict degradation pathway and toxicity. The procedure was validated by robustness, selectivity, linearity, precision, and accuracy. Liquid chromatography was performed in a Phenomenex® RP-18 column with a mixture of acetonitrile and 0.3% (v/v) triethylamine solution as a mobile phase in isocratic elution. Results and conclusions: The method demonstrated robustness, good recovery, precision, linear response over a range from 5.0 to 40.0 μg.mL-1, and to be stability indicating. The alkaline stress condition resulted in the formation of DP-1. hrms studies identified this product as an hydroxyacetamide derivative, and in silico studies did not show toxic potential.
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