Chemicals are generally divided into pharmaceutical intermediates and APIs in the pharmaceutical industry. Pharmaceutical intermediates are actually some chemical raw materials or chemical products used in the process of drug synthesis, advanced intermediate products used in the synthesis of chemical drugs, and "semi-finished products" in the process of chemical drug synthesis.

The API refers to the raw material used in the production of various preparations. It is the active ingredient in the preparation. Various powders, crystals, extracts, etc. prepared by chemical synthesis, plant extraction or biotechnology are used for medicinal purposes. Substances that the patient cannot take directly.