Solvent Use and Waste Issues

Pervaporation as a green drying process for tetrahydrofuran recovery in pharmaceutical synthesis

“…The product refers to the active pharmaceutical ingredient (API) in the final drug formulation. This waste is mainly composed of organic solvents, which typically ranges from 50% to 60% by mass (2,3). These solvents are used for the various unit operations in pharmaceutical manufacture from facilitating reactions to various separation and purifications.…”

“…Solvent usage not only adds to the direct inprocess waste for pharmaceutical operations but also accounts for a significant amount of the carbon footprint in drug manufacture (3). Energy use and emissions generated through the solvent life cycle can be large.…”

“…One of the areas of interest in designing greener processes is solvent recovery (8). Distillation is the predominate process for solvent separations in chemical processing, accounting for over 90% of the commercial operations (9).…”

“…Although many do not consider it a green technology because of its relatively high energy requirements and process inefficiencies, which result in greenhouse gas emissions (9). Currently, distillation is used for the majority of solvent separation processes in the pharmaceutical industry (3). Conventional distillation is a relatively straightforward method for separation of common solvent waste mixtures but is limited when dealing with those from the pharmaceutical industry where complex mixtures or azeotropes exit.…”

“…This case study assumes that this is being done with a pharmaceutical synthesis in the development stages, where purity can be assessed and changes made. Solvent recycling in pharmaceutical manufacturing can be performed only as long as the operation conforms to regulatory requirements and the recycled solvent does not affect the quality of the intermediate or API (3).…”