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Environmental contamination from mixtures of chemical substances and materials resulting from anthropogenic activities has adverse effects on aquatic biota. Fipronil (FP) is an insecticide widely used in agriculture and public health and is frequently detected in environmental compartments. Microplastics (MPs) represent another class of contaminants that have raised concerns due to their ability to adsorb pollutants, potentially acting as a vector. This study evaluated the influence of polyethylene microplastics on the toxicity of FP in zebrafish (Danio rerio) embryos/larvae. Zebrafish embryos were exposed to aqueous suspension containing purified FP and the FP + MP mixtures for 120 h. Mortality, teratogenicity and cardiotoxicity were observed during the zebrafish development. Larvae were more sensitive to FP than the embryo. The presence of MPs reduced lethality; however, no significant changes were observed for sublethal endpoints. Our findings demonstrate the acute impact of FP on zebrafish embryos/larvae, demonstrating that MPs interfere with toxicity. Therefore, understanding the mechanisms of interaction between contaminants of different classes is essential for predicting the associated risks to biota.

Aim: This study was aimed at determining the levels of trace elements in six medicinal plants of tropical origin. Methods: The levels of As, Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn in Albizia glaberrima (AG), Aristolochia ringens (AR), Brysocarpus coccineus (BC), Ipomoea asarifolia (IA), Sansevieria liberica (SL), and Telfairia occidentalis (TO) were determined using an inductively coupled plasma-mass spectrometry. The estimated dietary intakes of the metals, hazard quotients (HQ), and hazard index (HI) were calculated. Results: The highest levels of Cd, Pb, Zn, and Fe were detected in IA. BC had the highest levels of Mn and Ni while AR had the highest levels of Cu, Co, and As. However, the levels of the metals were mostly below the permissible limits in the plants. The estimated dietary weekly intakes (EWIs) were below the provisional tolerable weekly intake for each chemical element. The EWIs range values were 21.566–643.114 µg/kg per day (kg is the unit of body weight), 0.008–1.529 µg/kg per day, 0.6–7.815 µg/kg per day, 67.569–215.889 µg/kg per day, 4.305–185.451 µg/kg per day, 0.225–1.704 µg/kg per day, 1.03–10.2 µg/kg per day, 0.933–2.286 µg/kg per day, and 62.554–854.4 µg/kg per day for Cu, Cd, Pb, Zn, Mn, Co, Ni, As, and Fe, respectively. The HQ values of the elements were less than 1 except for Cu in AR (1.321). The values of lifetime cancer risks exceeded the permissible limit in all the plant materials. Conclusions: The findings from the study revealed that the consumption of TO, SL, and AG for medicinal purposes has no inherent non-carcinogenic toxicity while the consumption of AR, IA, and BC has some risks of non-carcinogenic toxic. However, the six plant materials showed inherent risks of carcinogenic events, as such their use for medicinal purposes must be cautious, maybe by reducing both the ingestion rate and the frequency of intake.

ABSTRACT Different solid forms of an active pharmaceutical ingredient can have distinct chemical and physical characteristics. In this work, we studied the solubility and dissolution properties of the described tibolone polymorphic forms (I and II). Both forms were successively recrystallized and characterized by powder X-ray diffraction and attenuated total reflection infrared spectroscopy. Equilibrium solubility and dissolution profiles were performed for both forms. Solubility studies demonstrated that form II is statistically more soluble in water, 0.01 mol L-1 HCl and pH 4.5 acetate buffer. The solubility of forms I and II were explained in terms of crystal packing. Dissolution tests of tablets showed a lower release of polymorphic form II than form I from tablets. The results showed an impact of polymorphism on the quality of tibolone tablets and suggest that tibolone forms I and II can show distinct interactions with pharmaceutical excipients used in tablets. Therefore, only form I is acceptable for the preparation of tablet forms. Based on our results, we propose the quality control on tibolone raw materials using X-ray diffraction analysis and attenuated total reflection infrared spectroscopy.