Scientists detail method to greener drug production.
Should this method be successfully harnessed on an industrial scale, the possibilities of an environmentally safer alternative could represent an incredible application for the pharmaceutical industry.
In addition, the prospect of not having to account for clean-up costs for toxic waste means a significant saving for chemical and drug manufacturing companies.
Researchers from the University of Wisconsin-Madison focused on a key step key step in the pharmaceutical production process, which produces a waste stream that they believe could be significantly reduced.
The manufacture of the majority of pharmaceuticals requires numerous processes consisting of a number of steps. Each step produces waste and when the drug synthesis uses harmful chemicals, the chemicals disposed are usually toxic.
Using technology developed and provided by pharmaceutical giants Eli Lilly, the study details a method that uses pharmaceutical reactor technology along with companion chemistry to blend hydrocarbons with oxygen diluted with nitrogen.
What is unique about the new reactor technology is the small footprint and adaptability to changing production demands of the pharmaceutical industry. Researchers noted the technology has been developed so it can work at the scales necessary for commercial drug production.
However, the researchers identified a potential stumbling block to this technique. Using oxygen as a green chemical in making drugs and at the amounts required for pharmaceutical production raises major safety issues.
The primary starting points for most pharmaceuticals and other industrial chemicals are hydrocarbons that have the potential to explode when combined with oxygen.
"While most drug companies recognize the potential of using oxygen as a way to reduce waste, they've been reluctant to consider it because of safety concerns," said Shannon Stahl, a UW-Madison chemistry professor and lead researcher of the study.
However, Stahl said that because of the technology incorporated into the new reactor technology aerobic oxidation could be, “scaled to levels of tons per year without significant modifications to the reactor design.”
Stahl, whose group over the last decade has been working with pharma to develop new aerobic oxidation methods that could be used in the future manufacture of drugs.
The study is all the more relevant after a number of high profile cases involving drug manufacturing and the resultant toxic waste products appeared in the news.
At the start of this month, a study by the US Geological Survey (USGS) found water used by pharmaceutical manufacturing facilities was being released into the environment with drug concentrations that are up to 1000 times higher than normal.
The findings of the study found current water treatment technologies inadequate to treat the wastewater used by the manufacturers.
Likewise a white paper published by information solutions provider Rockwell Automation found the pharmaceutical industry the least efficient of all chemical industries in terms of waste generated per unit of product.
The paper quoted statistics compiled by the US Environmental Protection Agency (EPA), who stated that pharmaceutical companies generated 530m tons of toxic waste in 2005; 90 percent of which was produced by a list of 20 solvents that included methanol, dichloromethane (DCM) and formaldehyde.
Stahl’s study: ‘Development of safe and scalable continuous-flow methods for palladium-catalyzed aerobic oxidation reactions,’ can be found here.
