Lyophilization Definition. Lyophilization is a simple dehydration technique where; The product mixture is frozen first and; Vacuum is applied to dry the product. Equipment used to conduct the lyophilization process is called Lyophilizer. The ice under the vacuum directly changes to vapor without attaining the liquid phase.

Freeze drying, also known as lyophilisation or cryodesiccation, is a low temperature dehydration process that involves freezing the product, lowering pressure, then removing the ice by sublimation. This is in contrast to dehydration by most conventional methods that evaporate water using heat.