APIs comprise the essential chemical compounds that lead to the desired effects of drugs. They can originate from various sources, including natural, synthetic, or biotechnological processes. Natural APIs may be derived from plants, animals, or minerals. Synthetic APIs, on the other hand, are created through chemical reactions in laboratories. With the emergence of biotechnology, biologics—API products derived from living organisms—have gained traction, especially in the treatment of complex diseases like cancer and autoimmune disorders.