The freeze drying process has important applications in the pharmaceutical and biotechnology industries, and pharmaceutical freeze drying is now a standard process used to stabilise, store or increase the shelf life of drug products and other biologicals.
Pharmaceutical Freeze Drying Process
Freeze drying pharmaceuticals uses a process called lyophilization to lower the temperature of the product to below freezing, and then a high-pressure vacuum is applied to extract the water in the form of vapour. The vapour collects on a condenser, turns back to ice and is removed. Finally, a gradual temperature rise extracts all remaining ‘bound’ moisture from the product. This process retains the physical structure and preserves the material for storage or transport.
Advantages of Freeze Drying Pharmaceuticals
With freeze drying, delicate, unstable or heat-sensitive drugs and biologicals can be dried at low temperatures without damaging their physical structure. Freeze-dried products can be reconstituted quickly and easily, which is particularly valuable in the case of emergency vaccines and antibodies, which need to be administered as quickly as possible.
Freezing alone has some major disadvantages:
- Maintaining frozen storage is costly and takes up a lot of space
- Transportation of frozen materials can be difficult and expensive
- Failure of freezing equipment would risk the total loss of the product