Safer solvent use in the pharmaceutical industry

Solvent guides for specific applications: chromatography 

In the realm of chromatography, the quest for greener, more environmentally friendly practices is paramount. Solvents play a crucial role in chromatographic processes, but the prevalent use of hazardous solvents such as dichloromethane (DCM) poses significant challenges.  

Peterson et al. (2014) have addressed DCM usage in chromatography in a thorough review of the subject. This focus is particularly relevant since flash chromatography represents a significant contributor to chlorinated solvent waste in academic and drug discovery laboratories. DCM is a commonly utilised chromatography solvent due to its characteristics as a non-polar eluent capable of dissolving a diverse range of chemical compounds. It is often paired with methanol (MeOH), with or without acidic or basic modifiers, for the purification of heterocyclic compounds. However, the widespread use of DCM raises concerns about its toxicity to humans, environmental risks, and the disposal challenges associated with its non-flammable nature, ruling out incineration as a viable option. 

Amgen has developed a chromatography guide designed to aid in the selection of solvent/eluent combinations as alternatives to DCM/MeOH mixtures (Taygerly et al. 2012). These charts are based on an extensive selection of drug-like molecules with diverse functionalities and physicochemical characteristics, enabling the identification of solvent mixtures that possess comparable elution strengths.