Preparative Chiral Separations – from Laboratory Scale to Production

Over the past few years, preparative chromatographic separation of racemic mixtures into their individual enantiomers has become an integral part of the development process for new drug entities. This is because the number of chiral drug candidates has been increasing, a not surprising development, given the asymmetric nature of the drug receptor sites. At an early stage in development it is essential to know the differences in activity and toxicity between the two enantiomers in order to maximize the effectiveness of the product while minimizing the possible negative side effects of the new drug. At this stage of the process there is practically nothing known about the chemistry and physical properties of the molecule and the fastest and most convenient way to the pure enantiomers is usually chromatographic purification. In contrast to other possible procedures, only a few mg of product and a few hours are needed to develop a chromatographic separation method – important for these new candidates where there may be only a few hundred mg of the product in the world.