Sustainable chromatography by design and rational sustainable buffer selection

Energy and water consumption for buffer preparation can be substantial, especially if WFI is used. Whereas chromatographic process development can target minimal buffer use, the indirect ecologic impact of buffers in bioprocessing is completely unknown. This is because sustainability analysis and life cycle inventories are rudimentary and not fit-for-purpose to be used as development goal during process development. Traditionally, the reduction of buffer volumes is already part of the current implemented process development goals, as lower buffer volumes also correspond to lower costs and faster processes. Besides manufacturing of novel chromatographic formats (like filters, monoliths, etc.) this leaves very little room for further improvements in direct reduction of consumed buffers, but the sustainability influence of the buffer species and buffer strength is completely open for investigation, not addressed yet, and easy to implement in any scale as design and development goal. Buffer species, buffer preparation and buffer concentrations are currently selected by tradition, or by development goals completely unrelated to sustainability and we can tap into that underdeveloped area to select buffers and concentrations that are equally performant from a bioprocess viewpoint, but with a significantly lower ecological footprint. To tackle and quantify the influence of buffers and buffer preparation on downstream processing, we propose: (1) The generation of a comprehensive life cycle inventory of common buffer species used in biotechnological production (2) an assessment of the potential maximum savings through changes in buffer species and buffer concentrations that can be achieved by this approach (3) a fast to use tool for process development to assess the life cycle impact of buffers to implement a sustainability related key-performance-indicator that can be followed during process development (4) and finally the generation of physical demonstration use cases as a proof of concept.