The criteria for candidate selection include a combination of factors such as efficacy, safety, pharmacokinetics, and the feasibility of large-scale synthesis. Efficacy is assessed based on the compound's ability to interact with the intended target and produce the desired therapeutic effect. Safety considerations involve an evaluation of potential side effects, toxicity, and any adverse reactions that may arise during clinical trials. Pharmacokinetic properties, including absorption, distribution, metabolism, and excretion, are thoroughly examined to ensure that the candidate can achieve and maintain the necessary concentration at the target site within the body.

Once selected, the drug candidates move into the early stages of clinical development, typically starting with Phase I clinical trials. These trials aim to establish the safety profile, dosage range, and pharmacokinetics of the candidate drug in a small group of healthy human volunteers. The careful and strategic selection of drug candidates is crucial at this stage, as it determines which compounds progress further into larger and more comprehensive clinical trials. The ultimate goal is to identify a candidate with a favourable balance of safety and efficacy, paving the way for its potential approval and commercialization as a new therapeutic intervention. The candidate selection process requires a multidisciplinary approach, involving medicinal chemists, pharmacologists, toxicologists, and other experts working collaboratively to make informed decisions based on the available preclinical data and the potential clinical impact of the candidate compounds.