In 2020, as a response to the climate emergency and the UN’s 17 sustainable development goals, AstraZeneca announced ambitions to deliver a carbon negative value chain by 2030. The development and manufacture of active pharmaceutical ingredients (APIs) is a significant contributor to the organisation’s carbon footprint. As a result, reducing carbon footprint and delivering a circular economy has become a significant challenge for process engineering in the development of drug substance. This presentation will explore how sustainability is considered during API development and manufacture, including topics such as the elimination and reduction of high-impact reagents, increasing process velocity and throughput, and the consideration of new modalities and continuous manufacturing. Similarly, it will explore new approaches for introduction of circularity, opportunities for waste management and environmental impact through Life Cycle Analysis. These opportunities will also be considered alongside barriers to sustainability by design, such as regulatory changes, quality restrictions and analytical challenges. Attendees will take away an understanding of AstraZeneca’s ambitious commitment to achieving a carbon neutral business, how this impacts the production and development of API, and how the various barriers are being addressed.