A Review on Chiral Stationary Phases for Separation of Chiral Drugs

The resolution of chiral drugs is important in pharmaceutical analysis. The enantiomers of a chiral drug having identical physical and chemical properties in an achiral environment can be distinguished in a chiral envirorunent provided that there are suitable interactions with a chiral selector. The enantiomers of a chiral drug can act differently with one enantiomer exhibiting pharmacological activity and the other exhibiting undesirable toxic effects. It is therefore critical to separate and analyze racemic drugs. The United States Food and Drug Administration guidelines, therefore, make it mandatory to market only the active enantiomer of chiral drugs. The availability of innovative chiral stationary phases makes the identification of enantiomers faster and effective. This review describes the different chiral stationary phases based on Pirkle type, protein, cyclodextrin, polysaccharide, ligand exchange, macrocyclic antibiotics and chiral crown ethers used in chiral chromatography. The various mechanisms involved in the chiral recognition of enantiomers are summarized.