Lyophilizers Qualification

Freeze drying (or lyophilization) is a technique used to remove water from a solution to leave a dry ‘cake’ as an end product. The dry product is much more stable than a solution. The reduced weight and volume is a big advantage and the removal of the water does not change the activity of the product. This technique involves freezing the product on a shelf using extremely low temperatures (typically –40 to –50°C), applying a vacuum and then slowly heating the product to ensure the ice turns into vapor. This removes the water content from product by a process called sublimation.

The critical parameters during freeze-drying are temperature (product and shelf) and pressure/Vacuum. These measurements are usually recorded with every cycle to determine when the product is dry. In addition to monitoring each cycle, freeze driers also require regular validation. This will generally involve temperature mapping of the shelves in the chamber, condenser cool down test, system evaluation test (Vacuum Pull-Down) to test Vacuum pumping system efficiency and Vacuum integrity test to show quality of seals, as well as validation of steam supplies for the SIP system.

As freeze drying is a rather expensive process most products being processed are within the pharmaceutical and biotechnology industries. Companies often use freeze-drying to increase the shelf life of products, such as vaccines and other injectables. By removing the water from the material and sealing the material in a vial, the material can be easily stored, shipped and later reconstituted to its original form for injection.

Lyophilization can also be performed in other industries like:

Food industry (example: freeze dried fruits, astronaut food supplies, instant coffee)

Technological industry:

• In chemical synthesis to make them more stable, or easier to dissolve in water for subsequent use
• In bioseparations as a late-stage purification procedure to remove solvents In bacteriology to conserve special strains

Conservation and preservation industry:

• Flowers
• AnimalsWater damaged books and documents