Chapter 11 - Green solvents for qualitative pharmaceutical analysis

Abstract

In the pharmaceutical industry, various types of solvents are used for processing, purification, and production of medicine. The solvents have various kinds of important physicochemical properties on which extraction potential depend. Green solvents are environmental friendly and characterized with important physical properties, such as biodegradability, and can be synthesized from diverse sources with less hazards compared with petrochemical solvents. The demand of green solvents has increased compared with other solvents because others have many disadvantages like high explosiveness, ferocity, and flammability. All over the world, green solvents including water, methanol, nitromethane, acetone, ethanol, dimethyl formaldehyde, dimethyl sulfoxide, hexamethylphosphoramide, acetonitrile, pyridine, and ammonia are commonly used for processing and purification of medicines. The green solvents can also be easily synthesized from alternative sources such as medicinal plants and other crops. For production of medicine, various pharmaceutical products or intermediates are required. Recently in the pharmaceutical sector, the purification of taxanthin, xanthene, benzoxanthenes, oleochemicals, crude glycerol, 2,3-butanediol, sildenafil citrate, sertraline, endothelin-A, celecoxib, and quinapril has been improved using green solvents. In medicine, solvents such as deep eutectic solvent, cyclic carbonates, ionic liquids, dimethyl carbonates, supercritical liquids (CO2 and H2O), limonene, and cymene are preferred over other solvents.