What is Lyophilization?

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Lyophilization is the creation of a stable preparation of a substance by freezing and dehydrating of the frozen product under high vacuum. Under controlled temperature and pressure, water sublimes moving from the solid into the vapor state. In the presence of protectants, many biological materials may be frozen and using a carefully controlled change in temperature and pressure, >95% of the water may be removed. This leaves the biological material both intact and active. This process is termed lyophilization and the specialized devices used to perform this process are termed freeze dryers.

Freeze-drying protectants include sugars that are naturally found in extremophiles, organisms that can withstand environmentally harsh conditions such as low temperature (cryobiosis) and drought (anhydrobiosis). Along with a combination of anti-oxidizing agents and bulking materials they form the “excipient” or “carrier” material for the dried biologic. They are usually the largest material by mass in the lyophilized product and form a “cake”, retaining the dried biologic ingredient in a stabilized state.