Active Pharmaceutical Ingredients refer to the raw materials used in the production of various preparations.
They are a variety of powders, crystals and extracts prepared by chemical synthesis, plant extraction or biotechnology, that are used as medicinal substances, but cannot be directly taken by patients. According to the demand for pharmaceutical preparations, the production of APIs can be divided into two types: sterile API production and non-sterile API production.

Sterile APIs do not contain any active microorganisms, such as molds, bacteria, viruses, etc., and are upstream products of pharmaceutical preparations.
Compared with non-sterile APIs, the production of sterile APIs not only requires strict control of chemical quality indicators such as product impurities and physical and chemical properties, but also requires higher standards for equipment, processes and environment to ensure sterility.

In sterile API production, the product is usually transferred into a solution state and then processed through sterile filtration. The intermediate materials or raw materials are formulated into solutions and passed through a 0.2 μm pore size filter to remove bacteria. The filtrate is then kept sterile through a series of refining operations, ultimately producing APIs that meet sterility requirements.

Take antibiotic APIs as an example.
Antibiotics refer to a class of secondary metabolites produced during the life activities of microorganisms (including bacteria, fungi, and actinomycetes) or higher animals and plants, which have anti-pathogenic or other biological activities. These compounds can interfere with the development or metabolism of other living cells.

Antibiotics are commonly used in clinical practice and are typically produced through microbial fermentation or semi-synthetic chemical processes. Representative products include penicillins, cephalosporins, and other widely used antibiotic compounds.

Filtration is widely used in different process stages of antibiotic API manufacturing, mainly including ultra-filtration concentration, decolorization filtration, sterilization filtration of gas, prefiltration and filtration of terminal products. The main filtration steps of the whole process are:

1. Security filtration: pre-filtration before ultra-filtration to protect downstream modules
2. Decolorization filtration: remove activated carbon particles to ensure filter cleanliness
3. Prefiltration: reduce microbial load and extend the service life of downstream sterile filter cartridges
4. Redundancy filtration: remove bacteria and microorganisms from the filtrate
5. Terminal sterilization filtration: remove bacteria and microorganisms from the final filtrate
6. Respirator balance tank pressure and prevent pollution