Benign-by-Design: Can Drugs be Eco-Friendly?
There’s been scuttlebutt recently about what happens to drugs that have been, to put it bluntly, flushed out of our bodies and down drains and toilets. Scientists are becoming increasingly worried about the drug waste that makes it out into the environment and accumulates. But what if drugs were engineered to be more eco-friendly in the first place?
Our own Sarah Everts took a look at the concept of building greener drugs in this week’s issue. As she says, “there is not yet an ecotoxicity equivalent to Lipinski’s Rule of Five,” the infamous set of parameters to predict the safety and orally-availability of a compound that were developed at Pfizer by Christopher Lipinski in the late 1990s. Still, scientists from academia and industry provided a few guidelines for a “benign-by-design” approach to medicinal chemistry:
--Adding ester bonds can help with biodegradability.
--Avoid quaternary carbons because they hinder biodegradability by microorganisms.
--Eliminating halogens, a culprit in making a drug environmentally persistent.
--Size matters, as bacteria cannot break down molecules that are too large.
--Getting rid of potentially environmentally-unfriendly blocking groups that aren’t involved with a drug’s activity.
--Increasing how efficiently drugs are absorbed when taken orally, so patients need to take less drug in the first place, lessening the amount that winds up in the environment
--Exerting more control over when and how a drug degrades.
Everts goes on to provide some examples of projects within pharma companies where a “benign-by-design” approach is yielding results. Still, there are hurdles, not the least of which is that an eco-friendly drug isn’t at the top of most companies’ priority list.
So, what are you thoughts on the potential of “benign-by-design”? Is this at all a consideration in your company or university’s labs?