Lyophilization is the proper term for freeze-drying. A wide variety of medical and pharmaceutical products are lyophilized, primarily for biological preservation. Some medical compounds – including commercial pharmaceuticals and bacteria cultures – are lyophilized as a part of their production.
Chemical or biological solutions are placed in a lyophilizer, usually on some sort of shelf system, and are frozen using very low temperatures (less than -30C). After freezing, water is removed via sublimation from the resulting “cake” using a vacuum inside the chamber.
ISO 13408 is the guiding document for equipment, processes, programs and procedures for the control and validation of lyophilization as an aseptic process.
