Chemistry in water:
Avoiding organic solvents for sustainable organic synthesis
Carlos Alvarez and João Sardinha of Hovione showcase the use of micellar chemistry in APIs
For decades, organic solvents have been the workhorse of the chemical industry, serving as indispensable media for numerous reactions. Traditionally, chemists have favoured organic solvents for their ability to facilitate a wide range of reactions. Their use has also been a cornerstone of pharmaceutical manufacturing.
However, this choice carries environmental consequences that cannot be ignored. As a major organic solvent consumer, the pharmaceutical industry significantly contributes to the generation of chemical waste, often containing hazardous byproducts that cause environmental pollution and disrupt ecosystems. Organic solvents are responsible for more than 80 % of pharma mass utilisation. 1
The E-factor, first introduced by Roger Sheldon and defined as the ratio of the mass of waste( typically including water) produced per mass of product, sheds light on the environmental impact of chemical processes. 2 In the pharmaceutical industry, E-factors can vary significantly, typically ranging between 25 and > 100.1 The high values observed in the
Figure 1 – Micelle with organic molecules in the core
context of chemical synthesis can be attributed to a combination of factors: complex synthetic routes, purity requirements, raw materials and scale-up challenges.
The pharmaceutical industry has become more committed in recent years to addressing environmental problems. Recovery strategies and waste treatment methods have been devised, leading to more sustainable processes. Local legislation also seeks to mitigate environmental impact, but a fundamental shift toward sustainable chemistry is still imperative to tackle the underlying causes of pollution.
Chemistry in water
The pharmaceutical industry is currently facing the need for a significant realignment, driven by rising demand for sustainable solutions, stricter regulations and increasing carbon taxes. Green Chemistry, as a movement within scientific research and industrial practice, highlights the need for environmentally friendly, cost-effective, socially responsible processes.
Around ten years ago, Professor Bruce Lipshutz and his research group at University of California, Santa Barbara laid the foundations
22 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981