Compared with the conventional drying method, the freeze dryer has obvious advantages!

Compared with the conventional drying method, the freeze dryer has obvious advantages!
The freeze dryer is one of the drying methods for the purpose of storing articles. The reason why the article will be damaged, rotted and deteriorated is mainly due to the external factors and internal factors, the external factors, the role of air, water, temperature, and biology; the internal cause is mainly the metabolism of the biological material itself. If the effects of external and internal factors can be reduced to a lower level, the object can be kept unchanged for a certain period of time. Freeze dryers are now widely used in the chemical, pharmaceutical, food, and scientific research fields, especially in biopharmaceuticals containing bioactive substances. Drying is a very old operation, but the heating and drying of powders and biological products often cause irreversible agglomeration of the particles. Especially in the preparation of ultrafine powders, the nanoparticles in the liquid phase will agglomerate into agglomerates that are difficult to disperse. This is mainly because the water in the ordinary particle drying process is emitted from the pores between the particles, and the surface tension causes an extremely high additional pressure to press the particles together to form a mass. This problem can be avoided by using a freeze dryer. The freeze-drying method first freezes the gel or blood to be dried into a solid, and then removes the water by gasification under a reasonable condition by sublimation, due to ice. The gasification process does not affect the coalescence state of the solid particles, so the original particles can be preserved without being compacted and agglomerated. In addition, the freeze dryer is usually suitable for processing biological products such as blood, because it has no high temperature operation, Prevent deterioration of biological products.
The products obtained by drying generally have problems of shrinking size and hardening of the texture. Most of the volatile components are lost, some heat-sensitive substances are denatured and deactivated, and some substances are even oxidized. Therefore, the dried product has a large difference in properties compared with that before drying. The lyophilization process is basically carried out below 0 ° C, that is, in the state where the product is frozen, and only when the residual moisture content of the product is lowered in the later stage, the product is allowed to rise to a temperature above 0 ° C, but generally does not exceed 40 ° C. Under vacuum conditions, when the water vapor is directly sublimated, the sample remains in the frozen ice shelf, forming a sponge-like porous structure, so the volume is almost unchanged after drying in a freeze dryer. Before using it again, as soon as you add water for injection, it will dissolve immediately.
Drying methods are various, such as drying, boiling, drying, spray drying, and vacuum drying, but ordinary drying methods are usually carried out at temperatures above 0 ° C or higher. The products obtained by drying generally have problems of shrinking size and hardening of the texture. Most of the volatile components are lost, some heat-sensitive substances are denatured and deactivated, and some substances are even oxidized. Therefore, the dried product has a large difference in properties compared with that before drying. The lyophilization process is basically carried out below 0 ° C, that is, in the state where the product is frozen, and only when the residual moisture content of the product is lowered in the later stage, the product is allowed to rise to a temperature above 0 ° C, but generally does not exceed 40 ° C. Under the vacuum condition, when the water vapor is directly sublimated, the sample remains in the frozen ice shelf, forming a sponge-like porous structure, so the volume after drying is almost unchanged. Before using it again, as soon as you add water for injection, it will dissolve immediately. The freeze dryer has the following advantages over conventional methods:
1. Many heat sensitive substances will not be denatured or inactivated.
2. When drying at low temperatures, some of the volatile components in the material are lost. Compared with the conventional drying method, the freeze dryer has obvious advantages!
3. During the lyophilization process, the growth of microorganisms and the action of enzymes cannot be carried out, so that the original traits can be maintained.
4. Since the drying is carried out in a frozen state, the volume is almost constant, the original structure is maintained, and concentration does not occur.
5. Since the moisture in the material exists in the form of ice crystals after pre-freezing, the inorganic salt-soluble substances originally dissolved in the water are evenly distributed in the material. When the product treated by the freeze dryer is sublimated, the dissolved matter dissolved in the water is precipitated, thereby avoiding the phenomenon that the inorganic salt carried by the internal moisture migration to the surface in the general drying method is precipitated on the surface to cause surface hardening.