Difference between revisions of "Active Freeze Dryers"

Freeze-drying or commonly known as Lyophilization is a gentle, but technically complex drying process during  which moisture is extracted from the frozen goods under vacuum  conditions. So, many liquid active pharmaceutical ingredients for the  pharmaceutical industry are quickly deep-frozen at temperatures of -70  to -100°C. Then, the frozen material is dried in a vacuum chamber. The  ice evaporates at under pressure without becoming liquid - it sublimates.  The water vapor is then extracted at increased vacuum and higher  temperatures. For some types, the encapsulation of the glass bottles  containing the ingredient is carried out under clean room conditions. Of  all types of drying, freeze-drying leads to the least product changes  and losses of ingredients.  The Freeze Dryers operate in 3 steps: freezing, main drying, final drying.  As from the second step, a vacuum pump is connected to the drying  chamber to initiate the sublimation. Here, extreme parameters are  reached. The vacuum sensor must withstand 5 x 10-3 mbar. This means no  external particles must enter into the drying chamber, as they would  contaminate the product.