Common Extraction Methods and Equipment (Essentials of Pharmaceutical Consultation for Licensed Pharmacists)

(1) Application of decocting method: It is suitable for medicinal materials whose active ingredients are soluble in water and stable to damp heat.

Features: economy, broad spectrum of extracted components, enzyme inactivation, glycoside protection and microorganism killing. However, there are many impurities leached, which is not conducive to refining, and the decoction is prone to mildew and deterioration.

The general process of decoction extraction is as follows: ① feeding; 2 soaking; ③ heating; ④ circulation; ⑤ Drainage; 6 slag.

Spherical frying pan (steamed ball) is mostly used for frying donkey skin in Ejiao production.

(2) Application of impregnation method: it is suitable for extracting viscous medicinal materials, organized medicinal materials, fresh and easily expandable medicinal materials and low-priced aromatic medicinal materials. Not suitable for precious medicinal materials, toxic medicinal materials and high-concentration preparations.

Features: the impregnation method is simple and easy, and the clarity of the preparation is good; Because the solvent is in a static state, the leaching of effective components is incomplete. Even if re-impregnation method, strengthening stirring or promoting solvent circulation are adopted, the leaching effect can only be improved, and high-concentration preparations cannot be directly prepared. It takes a long time and is generally not suitable for water as a solvent. Usually different concentrations of ethanol or liquor are used, so the impregnation process should be closed. According to the extraction temperature and soaking times, it can be divided into: 1. Cold impregnation method II. Hot dip method 3. Re-impregnation method.

(3) Application of percolation method: it is suitable for precious medicinal materials, toxic medicinal materials and high-concentration preparations; Extraction of medicinal materials with low content of effective components. However, for fresh and easy-to-expand medicinal materials, it is not appropriate to choose medicinal materials without organizational structure (contrary to impregnation method).

Features: Percolation method belongs to dynamic leaching, the effective components are completely leached, and the percolate can be collected directly without filtration. Different concentrations of ethanol or liquid are usually used.

Single percolation operation: ① crushing; ② wetting; (3) canning; ④ Exhaust; ⑤ impregnation; ⑥ Infiltration

(4) Characteristics of reflux method: reflux extraction method is more time-saving than percolation method, and the spectrum of extracted components is wider, but the clarity of the extract is poor. It is not suitable for the leaching of medicinal materials that are easily damaged by heat.

1. Reflux extraction method 2. Reflux cold immersion method.

(5) countercurrent leaching method 1. Trough group 2 countercurrent leaching method. Continuous countercurrent leaching (6) The basic principle of steam distillation: Dalton's law. Steam distillation is suitable for distilling substances with high boiling point (the boiling point of volatile oil is mostly 150 ~ 300℃).

1. water distillation (* * * water distillation)

2. water distillation 3. Steam distillation (7) Supercritical fluid extraction method In supercritical state, the fluid has the dual characteristics of gas and liquid, which not only has low viscosity and high diffusion coefficient similar to gas, but also has high density and good solubility close to liquid.

The advantages of this method are: ① fast extraction speed and high efficiency. ② Suitable for heat sensitivity; ③ The process is simple.

The disadvantages of this method are: ① the investment of disposable equipment is too large, and the technical parameter software is less; ② Suitable for extracting lipophilic and low molecular weight substances. The general operation flow is as follows: ① Preparation of supercritical fluid. ② tooth extraction. ③ Decompression separation.