From Racemates to Single Enantiomers - Chiral Synthetic Drugs over the last 20 Years.

Before 1985, most chiral drugs newly introduced annually to the market were racemates and only three to five drugswere launched yearly as single enantiomers. Since then,the situation has changed dramatically, with racemates being introduced only rarely to the market. In 2004,all the new synthetic drugs (13 in the world) were launched as single enantiomers.This article summarizes the change of chiral drugs in the last two decades from racemates to singleenantiomers and outlines the structural features of these new drugs and the manufacturing technologies appliedto introduce chirality to them - chirality pool, various types of resolutions and asymmetric syntheses,of which the new technologies developed recently are highlighted.