STEREOSELECTIVITY OF ANTIBODIES FOR THE BIOANALYSIS OF CHIRAL DRUGS

The use of immunoassay techniques represents an alternative approach t o the more common chromatographic methods for the determination of the concentrations of chiral drugs. In the development of the former tech nique, the inherent stereoselectivity of the antibodies used appears t o be an important parameter to be studied. The structural features of the drug, including the environment around the asymmetric center, the flexibility of the molecule and the ability of the molecule to undergo racemization, contribute to the molecule's ability to be recognized b y stereoselective antibodies. These parameters are intrinsic and can n ot be influenced by the investigator. On the other hand, other paramet ers can be modified to favor the raising of highly stereoselective ant ibodies. These include the synthesis of an appropriate hapten; the sel ection of an optimal spacer arm between the hapten and the carrier pro tein used for the immunization procedure; and the choice of appropriat e immunization and antibody-screening procedures. The purification of antibodies using affinity chromatography may also facilitate the selec tion of stereoselective antibodies.