Ecological impacts of pesticides on Astyanax jacuhiensis (Characiformes: Characidae) from the Uruguay river, Brazil.

Brazilian freshwater ecosystems are continuously exposed to pesticides and domestic sewage. The Uruguay River was chosen for this study because of its international importance, as it flows through Brazil, Argentina, and Uruguay. It receives contaminants such as pesticides and domestic residues. Thus, the aim of this study to assess the accumulation of pesticides in muscle of the fish Astyanax jacuhiensis, its biochemical responses, and the presence of pesticides in water. In total, seven pesticides were registered in water from both river sites. Eight pesticides were detected in fish muscle. The biochemical responses showed that brain lipid peroxidation (LPO) and protein carbonyl (PC) in A. jacuhiensis were higher in the summer. Muscle showed the highest LPO levels in the spring and the highest PC in the summer. Liver LPO and PC levels were higher in the spring and summer. In the gills, the PC was higher in the spring and the LPO in the spring and winter. In the brain and in the gills, glutathione-S-transferase activity was high in the summer and autumn. Catalase activity was lower during the winter and spring. Non-protein thiol (NPSH) levels were lower in the brain in the winter and spring. Muscle tissue showed lower NPSH in the winter (site 1). Liver NPSH showed increased levels in liver in the spring and winter (site 2). The biochemical results clearly is related to pesticides and/or to the presence of other contaminants in the water such as metals or domestic sewage. The accumulation of pesticides in fish muscle added evidence that pesticides have been used in the area surrounding the Uruguay River. In conclusion, the biomarkers assayed in the present study could be used in future investigations considering other sampling sites along Uruguay River.

Forced degradation studies and stability-indicating liquid chromatography method for determination of tirofiban hydrochloride and synthetic impurities / Estudo da degradação forçada e método indicativo da estabilidade por cromatografía líquida para determinação de cloridrato de tirofibana e impurezas sintéticas

SUMMARY This study aimed to develop and validate a stability-indicating liquid chromatography method for the determination of tirofiban hydrochloride and two synthetic impurities (impurity A and impurity C). The method utilizes a RP-18 column (250 mm x 4.6 mm; 5 µm) with the PDA detector for quantitation. A mixture of triethylamine 0.1% (acidified to pH 5.5 with phosphoric acid) and acetonitrile was used as the mobile phase at a flow rate of 1 mL min-1 with gradient elution. The method presented satisfactory linearity, precision, accuracy and robustness, as well as low limits of detection and quantification, which demonstrate sensitivity in the determination of tirofiban and impurities A and C. It was selective for the determination of the drug and impurities analysed, without interference of the degradation products generated under forced conditions, demonstrating the stability-indicating capacity of the proposed method. Tirofiban showed to be practically stable to oxidative (30% H2O2 for 24 h) and thermal (75 °C for 24 h) conditions, but presented degradation to UVA light and acid hydrolysis, obeying the first order kinetics for both. In this way, it can be used as a stability-indicating method in the quality control of the raw material of tirofiban hydrochloride, as well as of the finished product. The obtained results demonstrate the importance of deepening the studies in this area, to guarantee the quality of commercialized pharmaceutical products.

RESUMO Este estudo teve como objetivo desenvolver e validar método indicativo da estabilidade por cromatografía líquida para determinação de cloridrato de tirofibana e duas impurezas de síntese (impureza A e impureza C). O método utilizou coluna de fase reversa RP-18 (250 mm x 4,6 mm; 5 µm) e detector PDA para quantificação. A fase móvel foi composta por uma mistura de trietilamina 0,1% (acidificada com ácido fosfórico para pH 5,5) e acetonitrila, à vazão de 1 mL/min, no modo gradiente. O método apresentou linearidade, precisão, exatidão, robustez, bem como baixos limites de detecção e quantificação, demonstrando sensibilidade na determinação da tirofibana e impurezas A e C. O método apresentou seletividade na determinação do fármaco e das impurezas, sem interferência dos produtos de degradação gerados na degradação forçada da tirofibana, demonstrando sua capacidade indicativa de estabilidade. O fármaco apresentou-se estável a oxidação (H2O2 30% por 24 h) e a degradação térmica (75 °C por 24 h), mas degradou frente à luz UVA e hidrolise ácida, obedecendo cinética de primeira ordem para ambas. Dessa forma, pode ser utilizado como um método indicativo de estabilidade no controle de qualidade da matéria -prima do cloridrato de tirofibana, bem como no produto acabado. Os resultados obtidos demonstram a importância de aprofundar os estudos na área, com intuito de garantir a qualidade dos produtos farmacêuticos comercializados.

Occurrence and risk assessment of population exposed to deoxynivalenol in foods derived from wheat flour in Brazil.

Deoxynivalenol (DON) is the most important of the trichothecenes in terms of amounts and occurrence in wheat. This compound was shown to be associated with a glomerulonephropathy involving an increase of immunoglobulin A in humans. This study assessed the occurrence of DON in wheat flour and the exposure of Brazilian teenagers, adults and elderly to this mycotoxin due to intake of wheat flour-based products. DON extraction in wheat flour was carried out by solid phase extraction and the quantification was performed by ultra-high proficiency liquid chromatography with diode-array detection. A total of 77.9% of all samples were positive for DON, with concentrations ranging from 73.50 to 2794.63 µg kg-1. The intake was calculated for the average and 90th percentile of the contamination levels of DON in foods based-wheat for teenagers, adults and elderly in Brazil, and compared with the provisional maximum tolerable daily intakes (PMTDI). Females of all age groups were exposed to DON at higher levels when compared to males in regard of consumption of breads and pastas. Teenagers were the main consumers of foods derived from wheat flour, with maximum probable daily intakes of 1.28 and 1.20 µg kg-1 b.w. day-1 for females and males, respectively. This population is at an increased risk of exposure to DON due to consumption of wheat flour-based foods in Brazil.