Pulverization is an important part of Chinese medicine processing and Chinese medicine production. But there are some limitations in the powder’s granularity, powder extraction rate, powder collection rate and the conservation of effective ingredient by using the traditional crushing machinery. For some materials with special characteristics such as heat sensitivity, low melting point, components of medicinal material easily damaged, the traditional crushing machinery has no advantages. In addition, our country has abundant Chinese medicine sources. The extensive processing methods in the past can not meet with the production demands of Chinese medicine. Jet milling technology provides the new method for the better curative effect and varieties of ultra-fine Chinese medicine powders.
Jet milling technology and its features : Jet milling technology makes use of the materials under the function of high speed air with huge kinetic energy which can produce the high speed collision and intense friction between the powders, and at the same time, the high speed air produces the cutting function to the materials which achieves the purpose of smashing materials, and can process the raw materials into the ultra-fine powders (﹤10μm). This technology is almost widely used in all the processing industries such as chemical industry, medicine, food, plastics, mining, metal materials, etc. And it plays an important role in many special powder areas. It has many features as follows: 1. It has low smashing temperature and can smash the materials with heat sensitivity and low melting point. According to Joule - Thomson effect of high speed jet stream, when the air is jetted from muzzle with adiabatic expansion, the air can be cooled by itself which can counteract the heat produced by the collision and friction between powders. 2. It has shot production period and high powder collection rate. Because of the high speed collision and confined smash, the collision probability in the material room is large and there is no leakage of powders. 3. You can get the products with high purity (little pollution) and average granularity distribution (accumulated frequency reaches to over D95). 4. The materials which are smashed only by the wet smashing method can adopt the jet milling technology to be smashed by dried method. You can get the small and homogeneous powders. 5. It can realize a wide range of cooperation. The dried operation can be applied during the smash.
The notes of jet milling technology in the fine processing of Chinese medicine: ：jet milling technology is an advanced smashing technology. The research about jet milling technology applied the in fine processing of Chinese medicine has began just now and there are many problems exist. The technology whether can be controlled? Compared with the general inorganic minerals, Chinese medicine not only has the generality but also has its peculiarity. This smashing technology whether can be controlled is the key point that this technology whether can be applied in the fine processing of Chinese medicine. So we should research the following two aspects:
Firstly, combine the powder’s generality with Chinese medicine’s peculiarity to make the technological process: medicine materials → initial smashing → air smashing → cyclone separation → quality testing → packaging → finished product Secondly, filtrate and optimize the preparation process’s parameter
① Water drying: drying is for water control. And water affects the features of materials. It is generally believed that the materials can be easier being smashed with little water. The quantity of water is less than 4% is the guideline of filtration and optimization of drying methods, drying temperature, drying time and the other elements. ② Jet mill parameter: Jet mill’s main technology parameter includes grinding chamber’s diameter(m), smashing pressure(Mpa), feeding pressure(Mpa), air consumption (m3.min-1), treatment capacity (kg.h-1), air compressor power (kw), feeding granularity, etc. The selection of product granularity is the technical parameter of experimental indicator, orthogonal experimental design, and optimization of jet mill. ③ Powder’s classification parameter: the main parameters affecting the classified granule diameter are the rotate speed of rotor-type air classifier, feeding quantity and the secondary air flow. Take the classified granule diameter as the index of orthogonal filter powder’s classified parameter.
How to select product identification indicators: Chinese medicine powder is the aggregation of many single particles. The powder’s character not only is affected by the single granules, but also is related with interaction among the powders. Consequently, there are two kinds of important parameter to completely reflect the powder’s quality; they are the parameter of single granule and coefficient parameter of powder. But usually we take the basic technical parameter such as granule diameter, granule diameter distribution, specific surface area, wet ability and fluidity as the main research objects.
How to apply the ultra-fine powders of Chinese medicine: Firstly, solve the problem of powder aggregation. After the superfine-treatment, the substance’s specific surface area increases prominently. The surface energy is high. The fierce mutual attraction achieves the stable tendency. In order to avoid of the powder gathering and make the powder be in the single situation, we can adopt the appropriate surface treatment and packaging technology. Secondly, solve the technical problems existing in the course of chemical extraction. There are two methods of the Chinese medicine application. They are medicine extraction and direct medicine application. There are two problems in the view of extraction. One is the detraction problem of powders and the other one is the gelatinization problem during the course of extraction. This problem can be solved by extraction parameter of filtration and optimization. Thirdly, solve the technical problem of measuring outer dissolution. Viewing from the direct application of Chinese medicine, if you adopt the preparation made of ultra fine Chinese medicine powders, the key problem is the establishment of outer dissolution. The measures solving this problem are the inspection of dissolving medium and method, and the comprehensive selection of component indicators. Fourthly, solve the technical problem of pharmacodynamics authentication. Pharmacodynamic is the strongest verification means which can clearly show the effective components of Chinese medicine whether can keep and strengthen the effect of medicine.
Some literatures reported that the research of native ultra fine powder preparation and the traditional processing preparation show that the ultra fine powders can prominently improve the medicine effect. But the establishment of testing method needs the deeper research. The application and the foreground of jet mill technology in the Chinese medicine’s fine processing At present, there are a few of Chinese medicines developed by using jet milling technology. Only some unique and expensive fine materials of Chinese medicine adopt this technology. Only American ginseng, ginseng, pearl, panax notoginseng, pollen and the others are reported, but the experimental data is a few. And the persuasion is not strong. The development of some health products are just started which has not formed a vast market. The processing part introducing jet milling technology can create new smashing technology which not only richens the content of traditional processing, but also brings the new visage for Chinese medicine’s processing and manufacturing. It has become the new technology growing point of Chinese medicine industry. After the Chinese medicine is smashed ultra-finely, the touching areas with solvent increased during the course of extraction technology. Consequently, the method of extraction becomes easier, the time of extraction becomes shorter, transfer rate increases, which not only save the time, increase the production period, save the energy, but also improve the comprehensive utilization degree of raw materials. For the solid preparation made of powder as the raw materials, ultra fine smashing can prominently improve its appearance of characteristics, solubility, dissolution, specific absorption rate, adhesion, bioavailability and the other pharmacy parameters. In conclusion, take full advantage of jet milling technology can improve the Chinese medicine’s industrial technology.