Lyophilizer have 3 steps in freeze drying process, with an experienced operator, you can save energy and cost each batch.
Is the most important step, also is the first step of a lyophilizer, thoroughly freezing the raw material to solid phase is the insurance of a success freeze drying. Freeze drying can be done in a lyophilizer (if shelves with freezing function) or in deep freezers. The key of freezing is to find out raw material’s eutectic point and make sure freezer temperature is lower than that. Freezing stage is the insurance of dried products’ physical shape.
Some material, especially fluid, the freezing stage may also involve annealing treatment (rapid freezing cause large ice crystals, proper raise its temperature allow ice crystal grow), which could help protect cells from broken as well as short the drying time.
Primary drying is the secondary step of a lyophilizer, mainly remove water by sublimation, in this stage, water in solid phase sublimate to vapor and move to ice condenser, freezing on condenser coils surface, in this stage >95% water have removed.
In this stage, gradually and proper increase the shelves temperature could speed up the sublimation, but too much energy supply may cause glass transition.
Secondary drying is the last step of a lyophilizer, mainly remove the adsorption water. Higher temperature and vacuum needed in this step, after secondary drying, the shelves could reduce temperature and prepare harvest.
How lyophilization addresses sample storage challenges
Although it is a complicated process, lyophilization has become standard practice in many industries, including pharmaceutical, biotechnology, and agriculture. Given the adverse effects of heat and water, dehydration by lyophilization offers several advantages, from improved sample stability and purity to increased shelf life and reduced costs.
By removing the need to dehydrate by heating, lyophilization provides a convenient and safe method for long-term storage of lab samples and pharmaceutical products while preserving their activity.
As well as increasing shelf life, freeze-drying samples also reduces their weight and volume, helping cut down on shipping costs and environmental impact. Eliminating the need for shipping procedures designed to maintain sample stability, such as dry ice, also simplifies logistics and helps further reduce costs.
These benefits are especially advantageous when transporting samples and assays to developing countries with limited facilities and budgets. Long transportation distances and often hot and humid environments would otherwise put a substantial strain on cold chain transport and storage. With lyophilization, a temperature-controlled chain is not necessary.
An example of this can be found as long ago as World War II, which saw one of the first use cases of freeze-drying as a commercial technique(2). Lyophilization was used to render blood plasma and penicillin chemically stable and viable without refrigeration. As a result, both could be transported to their intended recipients regardless of cold chain transport availability. This process is still in use today.