Class I new drugs refer to drugs that have not been marketed and sold at home and abroad, while Class II new drugs refer to preparations that have changed the route of administration and have not been marketed and sold at home and abroad. Class I drugs mainly include APIs and their preparations made by synthetic or semi-synthetic methods; new effective monomers and their preparations extracted from natural substances or by fermentation; optical isomers in known drugs and their preparations made by splitting or synthesizing methods; Drugs prepared from multicomponent drugs already on the market into fewer components; new compound preparations; preparations already on the market in China to add new indications that have not been approved both at home and abroad. Class II refers to preparations that change the route of administration and are not yet marketed and sold domestically or abroad. The categorization of Class I, II and subsequent classes of drugs itself is not based on the quality of the drug or its direction of action, but rather on the process of development and the current scope of application of the drug.