Active Pharmaceutical Ingredient API

Bulk drug (ICH Q7A) : Any substance or mixture of substances intended to be used in the manufacture of a drug and, when used in the manufacture of a drug, to be an active ingredient of a drug. Such substances have pharmacological activities or other direct effects in the diagnosis, treatment, relief of symptoms, management or prevention of disease, or can affect the function or structure of the organism.

The active ingredient of a drug. Only when the API is processed into pharmaceutical preparations can it become medicine for clinical application.

According to its source, API is divided into two categories: chemical synthetic drugs and natural chemical drugs.