Drug Discovery and Preclinical Evaluation

Drug Discovery and Preclinical Evaluation of New Drugs

The following questions are designed in the style of GPAT, NIPER, UPSC Drug Inspector, AIIMS Pharmacist, Railway Pharmacist, SSC, ESIC & State Pharmacist examinations. They include factual, conceptual, application-based and tricky questions.

The discovery and development of a new drug is a long, systematic, and highly regulated process that begins with the identification of a promising biological target and ultimately leads to the approval of a safe and effective medicine. For pharmacy students and professionals preparing for competitive examinations such as GPAT, NIPER, UPSC Drug Inspector, AIIMS Pharmacist, Railway Pharmacist, SSC, ESIC, and State Pharmacist examinations, understanding the basic stages of drug discovery and preclinical evaluation is essential.

Drug discovery involves identifying molecules that can produce a desirable therapeutic effect. The process generally includes target identification, target validation, hit identification, lead identification, and lead optimization. During lead optimization, the chemical structure of a promising compound is modified to improve its potency, selectivity, solubility, stability, pharmacokinetic properties, and safety. A compound with a sufficiently favourable overall profile is selected as a potential drug candidate.

Before a new drug candidate can be administered to humans, it undergoes preclinical evaluation. Preclinical studies are conducted using laboratory and, where appropriate, animal models to obtain information about the drug's pharmacological activity, pharmacokinetics, and toxicity. Pharmacological studies help determine the mechanism and desired biological effects, while pharmacokinetic studies examine absorption, distribution, metabolism, and excretion (ADME). Toxicological studies assess potential harmful effects, including acute, repeated-dose, chronic, reproductive, developmental, genotoxic, and carcinogenic effects, as applicable.

The overall aim of preclinical evaluation is to establish whether the drug candidate has an acceptable benefit–risk profile and whether there is sufficient evidence to justify its investigation in humans. However, successful preclinical results do not guarantee that a drug will be safe or effective in humans because differences between experimental models and humans may influence the outcome.

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Dr Alok Bains

https://drive.google.com/file/d/1YgVdWQCxyCc0dA2zajDSn7CD8jbb2yZM/view?usp=drive_link