Emerging Chemical Upcycling and Repurposing Strategies for Waste Pharmaceuticals

Abstract

With the aging of population, improvements in health standards, and developments in the pharmaceutical industry, access to medication has become widespread, leading to accumulation of expired or unused drugs in households and, consequently a significant generation of pharmaceutical waste. When improperly disposed of, this pharmaceutical waste can contaminate soil and water, compromising the health of ecosystems. Many strategies to reduce pharmaceutical pollution have been suggested in the past, such as collecting and properly disposing of waste drugs through incineration, extending medicine expiration dates, providing a greater variety of package sizes to prevent leftovers, and better regulation of stocking and dispensing practices. However, what could be done with waste drugs besides reverse logistics and proper disposal programs? By answering this question, this review aims to provide an overview of drug repurposing strategies that can contribute to the valorization of pharmaceutical waste and integration into the circular economy. Through the literature survey, waste drugs were shown to be a valuable resource in diverse areas such as corrosion inhibition, electrochemistry, organic synthesis, fluorescence, nanotechnology, materials science, agriculture, flow improvement, surface science, and photocatalysis. This field of research is still relatively unexplored and yet promising, considering the current worldwide need for eco‐friendly industrial alternatives.