As discussed throughout this text, freeze-drying, or lyophilization, is the most effective technique for the long-term preservation of sensitive products, including biologicals, pharmaceuticals, cosmetics, and food. Indeed, the low-temperature sublimation of ice from previously frozen specimens allows a progressive and careful dehydration of materials which, most often, cannot be stored and distributed at ambient temperatures. Antibiotics, blood derivatives, vaccines, natural extracts from bacterial, vegetable, or animal origin, sensitive carbohydrates, proteins, or dyes are among the many different products which are still, today, processed by freeze-drying.

Dramatic advancements in biochemistry and genetic engineering, as well as the rising interest in pristine natural active substances, has again pushed freeze-drying into the limelight. Most of these materials are fairly unstable in solution and/or elevated temperatures, are difficult to filtrate, and need to be sterile if they are to be used for human parenteral injection. Accordingly, they have to be processed under strict asceptic conditions and be protected from outside contamination. Conversely, as is the case for antimitotic drugs used in cancer therapy, some of them are highly toxic and should not be released into the environment.