What is the significance of jet mill in pharmaceutical ultrafine grinding
In the pharmaceutical industry, there are many raw materials with different particle sizes. When these raw materials are processed in the next step, the different particle sizes and uneven density of the powder result in poor fluidity and easy layering. Ultra-fine grinding is the operation process of making a large solid material into an appropriate degree of fine powder. Under the combined action of various forces, the solid material generates stress. Under this stress, the material undergoes elastic deformation. When the stress exceeds a certain limit, the material will undergo plastic deformation. The crushing within the range of elastic deformation is called elastic crushing, and the crushing after plastic deformation is called primary crushing. Generally, polar crystal drugs are easily crushed, and most of them are crushed elastically. On the contrary, non-polar crystal drugs are mostly grinding, which is difficult to grind.
Jet mill can greatly reduce the particle size of solid materials and increase the surface area, which is of great significance to pharmaceutical engineering:
(1) It is helpful to increase the contact surface of solid and liquid dispersion medium, accelerate the dissolution rate of the drug, and improve the utilization rate of the drug;
(2) After the raw and auxiliary materials are micronized, the large particles are broken into fine powder, which facilitates the uniform mixing of several different solid materials, improves the uniformity of the dispersion of the main drug in the particles, and improves the dispersion of the colorant or other auxiliary materials;
(3) The improvement of drug fluidity is helpful to improve the quality of preparations, and it is also convenient to be processed into various dosage forms, which is convenient for dispensing and taking. The grinding process is a physical process, and objects exhibit different hardness and performance due to different cohesion. During grinding, the cohesion between molecules must be partially destroyed by external forces to increase the surface area of the drug, that is, the process of converting mechanical energy into surface energy. The external force used in the grinding process should be determined according to the hardness and performance of the drug.
Jet mill is a mature ultrafine grinding equipment, which is different from other ultrafine grinding equipment. The grinding principle is to use high-speed airflow to bring the animal material particles to move, so that the materials collide, collide, and rub against each other. Under the shearing action of the airflow, the material is ground into fine particles. Jet mills are widely used in ultrafine grinding of powdered medicines. The grinding process is continuous, with large capacity and high degree of automation; and the processed products have narrow particle size distribution, high purity, and particles with good activity and dispersibility.