Clinical trials are observations on clinical research. Prospective behavioural research studies on human beings to answer particular queries on biomedical or behavioural interventions. This creates data on safety and efficacy. In master protocol, multiple experimental treatments are tested in only one trail. Clinical trial protocol is used to describe and supervise the trail. This protocol contains a definite study plan to assure safety and health trails and to give a correct template for trail conduct to inspector. A clinical trial involves new drugs are classified into five phases. Each phase of the drug compliance is treated as a separate clinical trial. The drug-development process will move forward through all four phases. Phase 0 – pharmacodynamics and pharmacokinetics in humans (testing within 10 to 15 people). Phase 1 – screening for safety (testing within a small group of people 20 to 80 people). Phase 2 – establishing the efficacy of the drug (testing with a larger group of people 100 to 300 people). Phase 3 – final confirmation of safety and efficacy (testing with a large group of people 1000 to 3000 people). Phase 4 –safety studies during sales (post marketing studies describes additional information including the treatments risk, benefits, and optimal use).