Deuterated driven new chemical entities: An optimistic way to improve therapeutic efficacy.

In organic chemistry, the use of deuterium exchange as a tool to study the mechanism of chemical reaction has been well explored. Since two decades, the research focus on deuterated bioactive molecules has been gaining attention for investigating the therapeutic potential of deuterium replacement in a chemical structure. Recently, Food Drug Administration (FDA) approved the first deuterium-labeled drug "deutetrabenazine", and notified the deuterated drugs as new chemical entities (NCEs). Henceforth, the deuterium substitution driven structure activity relationship, preclinical pharmacokinetics, and toxicity studies were much initiated. Deuteration of a bioactive molecule often results in improved therapeutic efficacy due to the altered pharmacokinetic profile. This review provides a conceptual framework on the importance of deuterium atom in chemical structure of a drug, and its biological value in improved physiochemical properties, pharmacokinetics, biological target interaction, diagnosis, and toxicity. In addition, this review concisely updated the recent deuteration methods, chemical stability, challenges in drug development, deuterium-based imaging in diagnosis, and selected synthetic scheme of deuterated molecules.