Abstract
<jats:p>Pharmaceutical waste is a major environmental and public health problem because it can pollute ecosystems and lead to problems such as antimicrobial resistance. This chapter defines pharmaceutical waste as unused medicine, personal care products, and accessories that need special collection and disposal. It discusses the main sources of pharmaceutical waste, ranging from healthcare facilities, drug manufacturing, homes, veterinary and agricultural sectors, to illegal drug markets. The chapter also explores several classification approaches for pharmaceutical waste by chemical composition, level of hazard, physical state, and regulatory classifications to guide suitable disposal and treatment. It also explores some of the challenges in determining and classifying pharmaceutical waste, including inconsistency in international regulations, non-uniform systems, analytical complexity in trace detection, and information gaps on pharmaceutical environmental fate. Based on notable academic research, the chapter emphasizes the importance of understanding pharmaceutical waste sources and classification to develop effective management practices and prevent their negative effects.</jats:p>