Pre marketing clinical trials are clinical trials designed to obtain information about the effectiveness and safety of a new drug. Generally, it includes phase I, phase II and phase III clinical trials. Any new drug must go through the pre marketing clinical trial stage before it can be approved for marketing for a wide range of people. Now, the drug supervision and administration departments all over the world have stipulated that drugs must undergo pre marketing tests and undergo strict reviews before they are launched on the market to determine whether they are safe and effective. Pre marketing trials include animal efficacy and toxicity tests and phase I to phase III clinical trials. Obviously, the purpose of these trials is to prove the safety and effectiveness of the test drugs.