Green Chemistry Principle #1
It is better to prevent waste than to treat or clean up waste after it has been created.
Contributed by Berkeley W. Cue, Jr., PhD, BWC Pharma Consulting, LLC.
In their publication “Green Chemistry, Theory and Practice” in 1998, Anastas and Warner introduced their 12 principles. My view is the first principle, often referred to as the prevention principle, is the most important and the other principles are the “how to’s” to achieve it.
An often-used measure of waste is the E-factor, described by Roger Sheldon, which relates the weight of waste coproduced to the weight of the desired product. More recently, the ACS Green Chemistry Institute Pharmaceutical Roundtable (ACS GCIPR) has favored process mass intensity, which expresses a ratio of the weights of all materials (water, organic solvents, raw materials, reagents, process aids) used to the weight of the active drug ingredient (API) produced. This is an important roundtable focus because of the historically large amount of waste coproduced during drug manufacturing—more than 100 kilos per kilo of API in many cases. However, when companies apply green chemistry principles to the design of the API process, dramatic reductions in waste are often achieved, sometimes as much as ten-fold. So, it is important to extend the impressive results achieved by the ACS GCIPR to all parts of the drug industry, especially the biopharma and generic sectors, as well as to other sectors of the chemical enterprise where synthetic chemistry is used to produce their products.
More Resources & Examples:
2012 PGCCA Winner: Codexis, Inc. and Professor Yi Tang, University of California, Los Angeles “An Efficient Biocatalytic Process to Manufacture Simvastatin”
2002 PGCCA Winner: Pfizer, Inc. “Green Chemistry in the Redesign of the Sertraline Process”
Pharma Strives for Green Goals, Stephen K. Ritter, Chemical & Engineering News, 90(22), May 28, 2012.
The E Factor: fifteen years on; R.A. Sheldon; Green Chem. 2007, (9), pp 1273-1283, DOI: 10.1039/B713736M
Using the Right Green Yardstick: Why Process Mass Intensity Is Used in the Pharmaceutical Industry to Drive More Sustainable Processes; Concepcion Jimenez-Gonzalez, Celia S. Ponder, Quirinus B. Broxterman, and Julie B. Manley; Org. Process Res. Dev., 2011, 15 (4), pp 912–917, DOI: 10.1021/op200097d.