Safer Solvents for Active Pharmaceutical Ingredient Purification Using Column Chromatography.

Column chromatography is a technique widely used for the purification of active pharmaceutical ingredients (APIs). One of the common solvent systems used by this technique is blends of dichloromethane (DCM) and methanol (MeOH), thereby exposing workers to health and safety risks and making the pharmaceutical sector one of the major contributors to chlorinated solvent waste. In this work, API separation and purification using several alternative safer solvent blends in column chromatography were evaluated and compared to DCM/MeOH. Ibuprofen and acetaminophen were used as model APIs, and caffeine was used as a model additive. Overall, some of the safer solvent blends tested provided better performance, with higher API recovery and purity compared to DCM/MeOH, in addition to potential health, safety, and environmental benefits. Specifically, blends of heptane/ethyl acetate and heptane/methyl acetate showed the most promise. Our work demonstrates the potential of these safer solvent blends as possible replacements for DCM/MeOH in API purification, thereby addressing a critical safety concern in the pharmaceutical industry.