Measurement and Reduction of Organic Solvents in Pharmaceutical Manufacture
C. Stewart Slater1, Mariano J. Savelski2, and Robert P. Hesketh2. (1) Rowan University, 201 Mullica Hill Road, Chemical Engineering, Glassboro, NJ 08028-1701, (2) Chemical Engineering, Rowan University, 201 Mullica Hill Road, Chemical Engineering, Glassboro, NJ 08028-1701
The pharmaceutical industry is typically one of the largest users of organic solvent per amount of finished product. The average mass intensity in the pharmaceutical industry is also very high compared to other chemical processing industries due to the multi-step synthesis and batch processing methods used. Through an EPA funded grant, Rowan University, in collaboration with a pharmaceutical industry, has been working to develop methods to quantify and ultimately decrease the amount of solvents used in pharmaceutical manufacture. Through a unique academic-industrial partnership program, “engineering clinics” a student team has worked with Bristol-Myers Squibb to gain an insight into the issues related to pharmaceutical processing. A spreadsheet based method, solvent selection table, has been developed to show environmental impacts of solvents commonly used in the pharmaceutical industry based on environmental parameters. The table allows for a quick comparison of the “greenness” two alternate processes using different solvents. In addition to solvent metrics, an examination of solvent processing was undertaken with the goal to recover or reduce the amount of solvents used. Pervaporation was studied as a replacement to distillation for dehydration of azeotropic organic solvent/water process streams. Pervaporation has the potential to effectively dehydrate organic solvent-water mixtures. Studies have been conducted with solvent-water mixtures of tetrahydrofuran and ethylacetate-water. Results and process applications will be discussed.