Chiral Drug Separation

Consideration of chirality is now an integral part of drug research and development and the regulatory process. There is no choice! Enantiomeric forms of a drug can differ in potency, toxicity, and behavior in biological systems. Enantiomers of all chiral bioactive molecules have to be separated and tested. The Food and Drug Administration (FDA, U.S.A.), and regulatory authorities in Europe, China, and Japan have provided guidelines indicating that preferably only the active enantiomer of a chiral drug should be brought to market. This entry discusses the main chiral drug separation methods, viz. gas chromatography (GC), highperformance liquid chromatography (HPLC), capillary electrophoresis (CE), and some new techniques. The first part presents the concept of molecular chirality and some examples of chiral drugs. The importance of chiral drug separation is briefly discussed. The second part describes the main chiral drug separation techniques and related chiral recognition mechanisms, as well as available chiral selectors. Some typical examples are given, and the pros and cons of chromatographic and capillary electrophoretic techniques are compared. Readers are also referred to specialized review articles for details. The last part summarizes and briefly discusses future development trends in chiral drug separation techniques.