Hazard screening of photo-transformation products from pharmaceuticals: Application to selective β-blockers atenolol and metoprolol.

The identification of toxic components in cocktail mixtures of pollutants, their metabolites and transformation products (TPs) generated from environmental and treatment processes remains an arduous task. This study expanded in this area by applying a combination of chemical analytics, a battery of in vitro bioassays and an in silico "testing battery" to UV photolysis mixtures of active pharmaceutical ingredients. The objectives were to understand the toxic nature of the mixtures and to prioritize photo-TPs for risk analysis.

Transformation products in the water cycle and the unsolved problem of their proactive assessment: A combined in vitro/in silico approach.

Transformation products (TPs) emerging from incomplete degradation of micropollutants in aquatic systems can retain the biological activity of the parent compound, or may even possess new unexpected toxic properties. The chemical identities of these substances remain largely unknown, and consequently, the risks caused by their presence in the water cycle cannot be assessed thoroughly. In this study, a combined approach for the proactive identification of hazardous elements in the chemical structures of TPs, comprising analytical, bioanalytical and computational methods, was assessed by the example of the pharmaceutically active micropollutant propranolol (PPL).

Initial hazard screening for genotoxicity of photo-transformation products of ciprofloxacin by applying a combination of experimental and in-silico testing.

Ciprofloxacin (CIP) is a broad-spectrum antibiotic found within μg/L concentration range in the aquatic environment. It is a known contributor of umuC induction in hospital wastewater samples. CIP can undergo photolysis to result in many transformation products (TPs) of mostly unknown toxicity.

Environmental risk assessment of anti-cancer drugs and their transformation products: A focus on their genotoxicity characterization-state of knowledge and short comings.

Anti-cancer drugs are chemotherapeutic agents that are designed to kill or reduce proliferating cells. Often times, they interfere directly or indirectly with the cell's deoxyribonucleic acid (DNA). Some of these drugs can be detected in the ng/L concentration range in the aquatic environment and have the potential to be very persistent.

Modification of the umu-assay (ISO 13829) accounting for cytotoxicity in genotoxicity assessment: a preliminary study.

In this study, the umu-assay (ISO 13829) was modified by addition of the resazurin-reduction assay to assess the cytotoxic potential of toxins. The aim was to develop a test system that was capable of examining both genotoxicity and cytotoxicity on the basis of the metabolic health of the cells so as to provide a better assessment of the negative influence of toxic effects on the evaluation of genotoxicity. The test was established and validated with mitomycin C (MMC), 1,3-dinitropyrene (1,3-DNP), 4-nitroquinoline-1-oxide (4-NQO) and chloramphenicol (CHL) as toxins with known responses in the umu-assay.