The extraction and separation methods of effective components in Chinese herbal medicines are briefly described.

The extraction and separation methods of Chinese herbal medicines include supercritical fluid extraction, membrane separation, ultrafine grinding, traditional Chinese medicine flocculation separation, semi-bionic extraction, ultrasonic extraction, cyclone extraction, pressurized countercurrent extraction, enzymatic method, macroporous resin adsorption, ultrafiltration, molecular distillation and so on. Details are as follows:

1, supercritical fluid extraction

Using supercritical fluid as extractant, the effective components of traditional Chinese medicine are extracted from liquid or solid and separated. Its principle is to use supercritical fluid to extract effective components from the target at a temperature and pressure higher than the critical temperature. When it returns to normal pressure and temperature, the components dissolved in the fluid are immediately separated from the liquid gaseous fluid dissolved in the absorption liquid.

2. Membrane extraction separation technology

The basic principle of separation is to use the molecular weight difference of chemical components to achieve the purpose of separation. In the application of traditional Chinese medicine, bacteria, particles and macromolecular impurities (colloid, tannin, protein and polysaccharide) are mainly filtered out or decolorized.

3. Ultra-fine grinding technology

By using ultrasonic crushing and ultra-low temperature crushing technology, the central particle size of medicinal materials is below 5 ~ 10 micron, and the cell wall breaking rate reaches 95%. Effective components are easy to be extracted and directly absorbed by human body. It is suitable for all kinds of medicinal materials with different textures, and can directly expose effective components, thus making the dissolution and action of pharmaceutical components more rapid and complete.

4, drug flocculation separation technology

Flocculant is added to the water extract of traditional Chinese medicine. Through the adsorption, bridging and flocculation of flocculants and the coagulation of inorganic salt electrolyte particles and surface charges, many unstable particles such as protein, manganese liquid and saddle are connected to form flocs and settle, and the purpose of separation and purification is achieved through filtration.

Extended data:

The extraction and separation of Chinese herbal medicines have gone through three stages of development. The first stage is the traditional Dan, pill, ointment and powder; In the second stage, the extraction and rough treatment technology based on water-alcohol method or alcohol-water method is combined with modern industrial preparation technology to make Chinese patent medicine; The third stage is the modern plant medicine refined and quantified by modern separation technology and detection technology.

The three stages of plant medicine only show the time sequence of their successive production, which does not mean that the latter stage will replace or cancel the previous stage. Just as chemicals can't cancel natural drugs, biological drugs can't cancel chemicals. But the latter level embodies or applies modern science and technology more than the former level.

Plant extract and modern plant medicine overlap in concept and contain part of each other. Modern botanical drugs are largely based on extracts, which are the main raw materials and components of modern botanical drugs; However, some varieties of plant extracts are directly used as medicine.

Baidu encyclopedia-extraction of traditional Chinese medicine