Chiral pharmaceuticals in environmental samples

This chapter explores the environmental dynamics of chiral pharmaceuticals, focusing on their sources, analysis, occurrence, and enantioselective behavior. Chiral pharmaceuticals enter the environment at various stages of their life cycle, including manufacturing, improper disposal, human excretion, and veterinary use, contributing to significant contamination of wastewater, surface waters, and sediments. Their environmental chemodynamics are influenced by several factors, including sorption, microbial transformation, transport, physicochemical properties, and environmental conditions, all of which can lead to enantiomeric enrichment. Sorption studies, though scarce, sometimes reveal enantioselective interactions between enantiomers and environmental surfaces, whereas microbial transformation often demonstrates enantiomer-specific degradation patterns, with differences across environmental matrices. Wastewater treatment plants often show enantioselective degradation under controlled conditions, whereas surface waters exhibit variability due to oxygen availability and flow dynamics. These processes lead to differential persistence and toxicity of enantiomers, necessitating enantiomer-specific risk assessments. By integrating enantioselective data, this chapter provides insights into the management of the environmental impacts of these compounds, advancing both research and regulatory frameworks.