“Clinical trial” means a systematic study of new drug(s) in human subject(s) to generate data for discovering and / or verifying the clinical, pharmacological (including pharmacodynamics and pharmacokinetics) and /or adverse effects with the objective of determining safety and / or efficacy of the new drug. The process of drug development can be broadly classified as pre-clinical and clinical. Pre-clinical refers to experimentation that occurs before it is given to human subjects; whereas, clinical refers to experimentation with humans. Within the realm of clinical research, clinical trials are classified into four phases: Discovery Phase, Pre-Clinical Phase, Clinical Phase and Commercial Phase.
This topic describes: Types of Clinical Trails (According to u.s NIH), Classification of Various phases of clinical trials, Distinctive features, Purpose, Study Design, Subjects involved, No. of subjects and Length of Studies.