There’s a lot to learn – let alone keep in mind – when it comes to the challenging task of freeze-drying food or pharmaceutical products. Our experts have compiled the most relevant information about lyophilization for you here.
Also called lyophilization or sublimation technique
Drying of foods or pharmaceuticals, for example, in a frozen state
Transition of water from solid to gaseous state without passing through the liquid phase
Drying method that is the most gentle to products
The dried material is called lyophillisate
Products are placed on the temperature plates in a device and cooled down to below -18 °C by the surface temperature of the plate. Once the freezing temperature is reached, the chamber is evacuated, typically requiring a vacuum of less than 200 mbar.
In this stage, the temperature of the plates is increased. Depending on the product, the temperature can rise to 0 °C to 15 °C. The product's liquid is slowly removed without liquefying due to the very slow heating of the plates. Primary drying is the most crucial phase in freeze-drying.
In the secondary drying, the tightly bound water is finally converted into water vapor by further increasing the temperature to over +50 °C, reducing the water content to 0.5 – 3%.
Qualification of the plate temperature with five measuring points per plate
Measurement of the plate temperature with testo 190 T3/T4 or testo 191 T3/T4 plus probe holder for freeze-drying
Steam in Place (SIP):
Subsequent sterilization of the system with superheated steam under specified time and temperature conditions
DIN EN ISO 13408-1:
Requirements for the development, validation and routine control of aseptic processing for health care products
DIN EN ISO 13480-3:
Describes all relevant specifications for freeze-drying
testo 190/191 system consisting of data loggers, software and multifunction case
Large measurement data memory for long measurements
Measuring range -50 to +140 °C for use in freeze-drying and SIP
Probe holder as an accessory, in conjunction with the flexible probes for the data loggers testo 190 T3/T4 and testo 191 T3/T4, for optimum measurement on the plate
Downloads for the testo 190 CFR data logger system
Whitepaper, application example, product brochure and factsheet