By Stages

       People's endless pursuit of health has stimulated the continuous innovation and development of drug developers for different therapeutic drugs. In the experimental medical behavior, the most common test is the project of new drugs.
       In the test process, in order to reduce test risk, as far as possible protect the life safety, according to the provisions of Article 31 of the measures for the administration of drug registration, clinical trial division for four phases: phase I: clinical observation of human for new drug tolerance and medicine generation of dynamics, dosing regimens provide the basis for establishing.
       II phase: preliminary evaluation of treatment effects can be based on specific research purposes, using a variety of forms, including a randomized double blind controlled clinical trial. Phase III: confirmatory stage of treatment. On the basis of previous studies, further validation of drugs for the treatment of patients with target indications and safety, but also to confirm the role of the stage of treatment. Finally, to provide sufficient basis for the approval of the drug registration application, the general should be a random blind test with sufficient sample size. IV phase: the clinical application of the new drug into the market by the applicant.
       The aim was to investigate the drug treatment and adverse drug reaction under the conditions of wide use, and to improve the dosage of the drug.