The lyophilization process

As a basic principle, lyophilization has its advantages for filling if the medication is not sufficiently stable in solution and/or if the exact dosage is not possible using a dried filling.

In addition, lyophilization could also be of benefit if a product possesses one or more of the following criteria:

Instability with regard to humidity or oxygen Heat incompatibility Minimal use of agent amounts (high effectiveness, small dosage) Exact dosage as possible Complete rehydration as possible High quality product

Automatic loading of a freeze-dryer

Lyophilization is comprised of three procedual steps:

1. The freezing of the medication in the final container at very low temperatures, e. g. -60°C
2. The main drying (by delivering energy under a high vacuum, water or the solvent is extracted from the agent
3. Final drying

The process is carried out under aseptic conditions and takes approx. 2 days (differs depending on the agent and the application system).

Compared to common drying procedures, lyophilization protects the agent from denaturation caused by heat since the agent remain as frozen throughout the entire process. Medications which are processed in this manner can be stored up to three years provided best conditions - while the same combination of agents in liquid form can become useless within a few days. A further benefit of lyophilization: During the course of the procedure, no significant changes occure in the agent and consequently, risk of possible loss of biological activity is reduced comparing it with common filling processes. By virtue of its shelf life, the lopyhilized product can also be reconstituted in a minimum of time.