| Abstract: | This paper gives an overall view of the physical and technical processes that take place during freeze-drying. Freeze-drying is the careful drying of a frozen product under vacuum, at temperatures below the freezing point of the product. The design and co-ordination of the individual components of the freezedryer are decisive for the quality of the final dry product. Here, the peripheral processes that are necessary for production as well as economical aspects must also be taken into account. Thus, the growing demands made in the past few years by national and international health authorities with respect to sterility and safety against contamination during the course of production now also have an influence in freezedrying processes and equipment. In this respect, the ?human”? contamination risk represented by operators in the sterile area is being reduced by – for example – the use of automatic loading and unloading systems. Maintaining Class 100 clean room conditions is a pre-condition for aseptic production. This paper show that freeze-drying – and in particular the peripheral technology that has such a strong influence on the course of production – is improving continuously. It is not to be expected that freezedrying technology will be replaced by another process in the foreseeable future. |
