Spray Drying In Traditional Chinese Medicine
Spray drying is one of the most advanced technologies for drying materials in the traditional Chinese medicine industry. The application of spray-drying greatly simplifies and shortens the process and time for the extraction of traditional Chinese medicines to semi-finished or finished preparations, and improves production efficiency and product quality as well. Here Hawach will introduce the spray drying working principle, and its applications in traditional Chinese medicine for your reference.
Spray drying working principle
The spray drying machine is a piece of hot-air direct drying equipment. When working, the atomizer (nozzle) decomposes the raw material liquid into mist droplets and sprays it in the hot airflow with a temperature of 120~300℃. The difference between the speed of the mist droplet and the hot airflow is used to make the material dry quickly within a few to ten seconds. The raw material liquid for spray drying may be a solution, an emulsion, a suspension, a molten liquid, or a paste liquid. The dried product can be made into powder, granule, agglomerate, or even hollow sphere according to process requirements.
Spray drying in traditional Chinese medicine
Here we introduce the applications of spray drying in traditional Chinese medicine.
1) Spray drying in traditional Chinese medicine — extract drying
Spray-drying is currently the most widely used in the drying technologies of traditional Chinese medicine extracts. Compared with other drying methods, it can be directly fed in the form of liquid and dried by a hot air stream. The hot air stream is in full contact with the material and the drying is fast.
2) Spray drying in traditional Chinese medicine — granulation
The earlier spray drying granulation method is to spray dry the extract of traditional Chinese medicine, and then follow the traditional wet or dry granulation. The latter is the commonly used spray drying or dry compression granulation method, and the more advanced granulation method is direct fluidized bed spray granulation, which can be completed in one step from the medicine extract to solid particles.
3) Spray drying in traditional Chinese medicine — microcapsule
The methods for preparing microcapsules include the solvent method, mechanical method, chemical method, and spray drying method. The spray drying method is an earlier and more practical method for preparing capsules. The basic principle of an industrial spray dryer to prepare microcapsules is that after the core material is evenly dispersed in the material solution, it is sprayed and atomized in a hot air stream, and the solvent that dissolves the material is quickly volatilized to obtain the microcapsule product.
4) Spray drying in traditional Chinese medicine — coating
Spray coating technology is one of the applications of spray drying technology. Spray coating belongs to the category of film coating technology, which means that the solid particles are rolled in a fluidized bed, the coating material is atomized into small droplets through a nozzle, and the material enters the fluidized bed thus forming a thin film on the surface of the suspended core particles.