Q-SA√ESS: a methodology to help solvent selection for pharmaceutical manufacture at the early process development stage
A practicable, LCA based methodology has been developed to evaluate the sustainability implications of solvent selection during early process development for a batch manufacturing process for an API. Q-SA√ESS (Quick Sustainability Assessment via Experimental Solvent Selection) structures the early use of existing tools to carry out initial solvent selection on the basis of EHS factors and suitability for the desired chemistry. The life cycle of the solvent has been divided into three stages: solvent manufacture, use in the batch process and end of life/recycling. The application of the methodology is illustrated for a single example of chemistry which has been taken through from development lab to process evaluation towards pilot scale. This demonstrates how the methodology helps to select the solvent giving the lowest overall environmental impact.