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The challenge and potentialimpact of solvent replacement in the pharmaceutical industry


The University of Alabama, Centre
for Green Manufacturing and Department of Chemistry, Tuscaloosa, AL 35487, USA
Member of Chimica Oggi
/ Chemistry Today Scientific Advisory Board

The pharmaceutical industry reported the generation of over 530 million pounds of waste (e.g., organic solvents, acids, bases, etc.) to the EPA’s Toxic Release Inventory in 2005 (1), primarily from common methods in drug discovery and manufacturing. Solvent usage alone typically ranges from 10-800 kg of solvent per kg of Active Pharmaceutical Ingredient (API) produced, making the pharmaceutical industry not only the highest waste generator, but also the largest consumer of organic solvents among chemical manufacturing industries (2). The E(nvironmental) factor (the ratio mass of waste produced in a process, including all processing materials to the mass of product produced) of pharmaceutical production is on average from 25 to > 100 kg of waste per kg of product; substantially higher than any other industry (3). This indicates excessive amounts of generated waste and, consequently, a greater negative environmental impact and higher costs.

Pharmaceutical API manufacturing is sophisticated, with multistep organic synthesis, including bond-formation steps, workup, and separation each in an associated solvent (5–15 volumes vs. the critical reagent). Solvents often dif ...