Green pharma is largely based on the study and recommendations put forward in a 1998 publication by Paul T. Anastas and John C. Warner, entitled Green Chemistry: Theory and Practice. The central tenet developed for this new approach to chemistry can be very easily applied to pharmaceutical development and manufacture. Broadly, green chemistry is;
…the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products.
In more detail, Anastas and Warner propose twelve principles which should be central to the planning and processes of pharmaceutical development and manufacture. They are:
- Prevention; design chemicals and processes that prevent or minimise waste
- Atom Economy; design efficient processes that essentially involve as few atoms as possible
- Less hazardous chemical synthesis; eliminate or minimise toxic substances used in processes
- Designing safer chemicals; eliminate or minimise the presence of toxic substances in the chemical being created or manufactured
- Safer solvents and auxiliaries; avoid using solvents, separation agents where possible. When they must be used, use the least toxic and most innocuous chemical.
- Design for energy efficiency; design processes and use technology with optimal energy efficiency and minimal waste.
- Use of renewable feedstocks; use renewable substances, stocks and ingredients over those which are depleting (ie, fossil fuels)
- Reduce derivatives; avoid chemical derivatives which generate waste
- Catalysis; use catalyst processes which are more efficient, use less material and produce a reaction repeatedly.
- Design for degradation; design chemicals which break down into innocuous substances and do not accumulate in the environment.
- Real-time analysis for pollution prevention; monitor and control all processes to minimise or eliminate byproducts
- Inherently safer chemistry for accident prevention; design chemicals that are ‘safe’ in all forms (solid, liquid, gas) and minimise potential for accidents, such as explosion, fires and environmental damage.
While not an established group or doctrine, the principles of green chemistry and its influence on modern pharmaceutical development and manufacturing have evolved rapidly and organically to give the industry several shining examples of drug companies, products and processes that are ‘benign by design’.