Freeze dryers are widely used in pharmaceutical, biological, chemical and food industries. Freeze-drying techniques are very suitable for heat sensitive substances such as antibiotics, vaccines, blood products, enzyme hormones and other biological tissues.
Application advantages of freeze dryer:
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 the 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 method 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 drug remains in the frozen ice shelf, forming a sponge-like porous structure, so the volume after drying is almost constant. Before using it again, as soon as you add water for injection, it will dissolve immediately.
Freeze-drying machine Compared with the conventional method, the lyophilization method has the following advantages:
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.
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 sublimating, the dissolved substances dissolved in water are precipitated, which avoids 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.
6. After drying, the material is loose and porous, and it is sponge-like. After adding water, it dissolves quickly and completely, and the original trait is almost immediately restored.
7. Since drying is carried out under vacuum, there is very little oxygen, so some easily oxidizable substances are protected.
8. Drying can eliminate 95%~99% of water, so that the products can be preserved for a long time without deterioration.