Drug discovery and development is a complex and lengthy process aimed at
producing therapeutic substances that can be both effective in terms of pharmacological
activity, specificity, good affinity to its target molecule, and safe for humans. It is a
necessary step due to many emerging diseases of microbial, parasitic and genetic
diseases affecting the entire world so that effective prophylaxis and treatment could be
provided. The successful process of discovering a new drug relies on proper discovery
and characterization of the lead compound followed by the preclinical studies that
ascertain the safety and efficacy of the newly discovered compound. A number of
information gathered from preclinical studies that, include information about the
formulation, dosage, delivery, pharmacokinetic, pharmacodynamic, mode of action of
the drug as well as its relation with other drugs when they interacted, could determine
the fate of the new drug’s approval by the regulatory agency for a clinical trial on
humans. Human clinical trials with the new drug under investigation are carried out on
volunteers in different phases with a common goal to ascertain the new drug's safety,
efficacy, and possible side effect in the actual environment. Since the human body is
more dynamic, optimal dosage and effect of other substances on the drug itself are
determined so as to ensure better treatment; satisfactory results from the human trial
could pave the way for application and approval for a human trial in phase IV where
the drug may subsequently go for commercialization but with strict monitoring for any
unforeseen side effect most especially in a vulnerable group. Although this is an
expensive, tedious and risky process for the pharmaceutical industry and volunteers,
which takes many years, it is necessary. This chapter discusses the necessary steps for
developing a new drug from the initial discovery from bench-top up to human trial and
commercialization as an over-the-counter drug.
Keywords: Clinical trial, Discovery, Drug, Efficacy, Lead compound, Pharmacodynamic, Pharmacokinetic, Toxicity.
