Review: CHIRAL INTERACTIONS AND CHIRAL INVERSIONS – NEW CHALLENGES TO CHIRAL SCIENTISTS

The interest in chirality and its consequences is not a new phenomenon. However, during the last decade it has raised increasing expectations due to scientific and economic reasons, the pharmaceutical industry being the main contributor and driving force. Advances in chemical technologies connected with the synthesis, separation, and analysis of pure enantiomers from racemates, together with administrative regulatory measures, have resulted in an increase in the number of newly registered chiral drugs containing only one of the enantiomers. Though the advantages of using single enantiomer like least possible side effects, reduced metabolic/renal/hepatic drug load and reduced drug interactions with an improved efficacy are so attractive the problems associated with the development of single enantiomer drugs are so challenging and many of them are left unsolved even today. In this article we mainly stressed upon chiral interactions, chiral inversions and impact of in vivo chiral interactions in every stage of the kinetics leading to stereoselective absorption, distribution, metabolism and excretion. Discussion about the rational use of chiral excipients which can enhance the eutomer/distomer ratio of enantiomer release versus time of a racemic drug was made. Finally we also mentioned the list questions which are gradually turning into unsolved challenges and threatening the future research in the chiral area.