Clinical Research Regulation: Various types of Clinical Study, Phases of Clinical Trial, Clinical Trial Protocol.. Drug discovery and development together are the complete process of identifying a new drug and bringing it to market. Discovery may involve Screening of chemical libraries Identification of the active ingredient from a natural remedy. Design resulting from an understanding of the target. Development includes 0 Studies on microorganisms and animals. Analytical method development and validation Clinical trials and ultimately regulatory approval. Drug Development/Approval Process.. Types of Clinical Study: Descriptive and Analytical.. Difference between Case Control and Cohort Study Phases of Clinical Study Phase 0: Phase 0 includes exploratory, first-in-human (FIH) trials that are carried out in accordance with FDA regulations. The single subtherapeutic doses are administered to 10 to 15 volunteers in phase 0 trials, which are also known as human micro dose studies. These trials provide pharmacokinetic data or aid in the imaging of certain targets without causing pharmacological effects. Phase 1: The initial evaluation of a medicine is done in phase I studies, which use fewer healthy human participants. Phase 1 typically involves 20 to 80 healthy volunteers who have the illness or condition. Patients are often only utilized when a drug's mechanism of action indicates that healthy individuals will not tolerate it. Nonetheless, researchers carry out Phase 1 studies in patients with that particular form of diabetes if a new medication is recommended for use in diabetic patients. Phase 2: The purpose of phase II studies, which involve larger patient populations (a few hundreds), is to confirm the results of phase I safety evaluations and examine the drug's efficacy. These tests are insufficient to determine whether the medicine will be effective in treating patients. Phase 3: Researchers plan Phase 3 studies to prove whether a product deals an action benefit to a specific people or not. Sometimes known as pivotal studies/ pilot, these studies comprise 300 to 3,000 volunteers. Phase 3 studies deliver most of the safety data. Phase 4: Phase 4 trials are conducted when the drug or device has been approved by FDA. These trials are also recognized as post-marketing surveillance involving pharmacovigilance and continuing technical support after approval. There are numerous observational strategies and assessment patterns used in Phase 4 trials to evaluate the efficacy, cost-effectiveness, and safety of an involvement in real-world settings.