APIs are defined as any substance or mixture of substances provided by chemical suppliers and intended to be used in the manufacture of a drug product and that, when used in the production of a drug, becomes an active ingredient in the drug product. Such substances are intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment or prevention of disease or to affect the structure and function of the body.
APIs are often referred to as “bulk pharmaceuticals,” and the chemicals usually get made in plants far removed from the facilities where tablets, oral suspensions and topical applications are made. Produced in bulk by chemical suppliers, almost all APIs are powders.
Chemical manufacturers in every country make bulk pharmaceuticals, but the leading chemical suppliers of APIs are in China and India due to mostly economies of scale.
Regardless of where an API gets made, it must meet the safety and quality standards set by the leading drug regulator in the country where it will be used. That is, Chinese and Indian bulk chemical manufacturers that export chemicals to the United States must be inspected and licensed by the FDA. Likewise, bulk pharmaceuticals produced by chemical suppliers for many countries in Europe are subject to standards established by the European Medicines Agency.