Chemical compounds that come as mirror-image pairs are referred to by chemists as<unk>  or handed molecules. Each twin is called an enantiomer. Drugs that exhibit handedness are referred to as<unk> .<unk>  that are equimolar (1:1) mixture of enantiomers are called racemic drugs and these are obviously devoid of optical rotation. The most commonly encountered stereogenic unit, that confers<unk> ity to drug molecules are stereogenic center. Stereogenic center can be due to the presence of tetrahedral tetra coordinate atoms (C,N,P) and pyramidal tricoordinate atoms (N,S). The word<unk>  describes the three-dimensional architecture of the molecule and does not reveal the stereochemical composition. Hence<unk>  drug" does not say whether the drug is racemic (racemic drug), single enantiomer<unk>  specific drug) or some other combination of stereoisomers. To resolve this issue Joseph Gal introduced a new term called unichiral. Unichiral indicates that the stereochemical composition of a<unk> is homogenous consisting of a single enantiomer. Many medicinal agents important to life are combinations of mirror-image twins. Despite the close resemblance of such twins, the differences in their biological properties can be profound. In other words the component enantiomers of a racemic<unk> may differ wildly in their pharmacokinetic, pharmacodynamic profile. The tragedy of thalidomide illustrates the potential for extreme consequences resulting from the administration of a racemate drug that exhibits multiple effects attributable to individual enantiomers. With the advancements in<unk>  technology and the increased awareness about three-dimensional consequences of drug action and disposition emerged specialized field<unk>  pharmacology". Simultaneously the stereochemical nomenclature system also evolved.
Chiral drugs
Antiviral drug
Antiemetic
Antiprion drug
Topological drugs
Antimanic drugs
Antacid
Antiparasitic