Abstract :
A clinical trial is a research study in human volunteers to answer specific health questions. Carefully
conducted clinical trials are fastest and safest way to find treatment that work in people and way to
improve health. Investigational trials determine whether experimental treatment or new ways of using
known therapies are safe and effective under controlled environment. Observational trials address
health issues in large groups of people or population in natural settings. Clinical trials aim to measure
therapeutic effectiveness and constitute an important and highly specialized form of biological assay.
In phase-I pharmacokinetics, safety, gross effects are studied on human volunteers, by clinical
pharmacologists. If the drug passes the test, it enters phase II testings, where pharmacokinetics, safety,
therapeutic efficiency are studied on selected patients by clinical pharmacologist, if passes hundreds
of selected patients are now studied, primarily for safety and therapeutic effectiveness by clinical
investigators in phase III. If this is passed the drug is now approved and marketed. Even after
marketing, physicians from various hospitals and clinics send their opinion about the drug, regarding
ADR, efficacy in phase IV.
Keyword :
Clinical Trials, New Drug Discovery, Drug Development