Active Pharmaceutical Ingredients
API, also known as active pharmaceutical ingredient, refers to any substance or mixture of substances used in the manufacture of drugs. Such substances are used in the diagnosis, treatment, symptom relief, treatment or prevention of diseases. It has pharmacological activity or other direct effects or can affect the function or structure of the body.
- Obtained from natural medicine. Natural medicine is an important part of medicine. For example, artemisinin, an effective antimalarial ingredient isolated from the traditional Chinese medicine Artemisia annua.
- Take existing drugs as first-comers.
1) Discover the active ingredients of the drug from the side effects of the drug. For example, the phenothiazine antipsychotic chlorpromazine and its analogs are developed from the sedative side effects of the similarly structured antihistamine promethazine.
2) Obtained through drug metabolism research. For example, the metabolites of antidepressants imipramine and amitriptyline, norimipramine and noramitriptyline, have stronger antidepressant effects than the original drug; oxazepam is the active metabolite of diazepam.
3) Leading with existing breakthrough drugs. For example, the research on lansoprazole and other prazols is based on omeprazole, which is more active than omeprazole.
- Obtained by screening with pharmacological model. Through combinatorial chemistry, a large number of chemical libraries with different structures are constructed without separation of mixtures. Through high-throughput screening, the components are found to have pharmaceutical activity and then separated, and the structure of the active compound is determined.
- Designed according to physiological and pathological mechanisms. For example: the study of fluorouracil takes the nucleotide uracil synthesized from DNA or RNA as the lead compound, and replaces the hydrogen at position 5 with fluorine, making it a metabolic antagonist of the normal metabolites of the organism, and is used as an antitumor drug