Definition
Active pharmaceutical ingredient (API), also known as active pharmaceutical ingredient, refers to any substance or mixture of substances used in the manufacture of drugs, which has pharmacological activity or other direct effects in the diagnosis, treatment, symptom relief, treatment or prevention of diseases, or can affect the function or structure of the body.
Source
1. Obtained from natural medicines. Natural medicines are an important component of drugs. For example, artemisinin, an antimalarial active ingredient isolated from the traditional Chinese medicine Artemisia annua.
2 .Use existing drugs as precursors.
1) Discover active pharmaceutical ingredients from drug side effects. For example: phenothiazine antipsychotic chlorpromazine and its analogs were developed from the sedative side effects of the structurally similar antihistamine promethazine.
2) Obtained through drug metabolism research. For example: the metabolites of the antidepressants imipramine and amitriptyline, desipramine and desitriptyline, have stronger antidepressant effects than the original drugs; oxazepam is an active metabolite of diazepam.
3) Use existing breakthrough drugs as precursors. For example: the research on lansoprazole and other prazoles is based on omeprazole, which is more active than omeprazole.
3. Obtained by screening using pharmacological models. Through combinatorial chemistry, a large number of chemical libraries with different structures are constructed without separating the mixture. Through high-throughput screening, the components are found to have drug activity and then separated, and the structure of the active compound is determined.
4. Obtained by design based on physiological and pathological mechanisms.
For example: the research on fluorouracil uses the nucleotide uracil synthesized from DNA or RNA as the lead compound, and replaces the hydrogen at the 5th position with fluorine, making it a metabolic antagonist of the normal metabolites of the organism, and used as an anti-tumor drug1.
Research methods and techniques
1 Chiral drugs and chiral pharmacology
2 Combinatorial chemistry
3 Combinatorial biocatalysis
4 High-throughput screening
5 Chemoinformatics
6 Bioinformatics
7 Cell and molecular biology
8 Structural biology
9 Molecular cloning
10 Protein engineering
11 Genetic engineering
12 Human genome
13 Transgenic technology
14 DNA chips
15 Anti-nucleotides
16 Apoptosis
17 Molecular simulation
18 Computer-aided drug design
19 Rational drug design
20 Virtual drug screening1