Why Supercooling Can Inhibit Ice Nucleation and How to Improve Freeze-Drying Performance

This document is an English translation of the technical note discussing supercooling, ice nucleation, polymer systems, freeze-drying risks, and process optimization.

Key Conclusions

• Supercooling does not guarantee successful freezing.

• Freezing requires both low temperature and stable ice nucleation.

• Polymer systems often inhibit water molecule organization, making nucleation more difficult.

• Deep supercooling can lead to small ice crystals, poor pore structure, and inconsistent drying.

• Earlier-loaded samples may perform better because they have more time to nucleate.

• Process development should focus on achieving uniform nucleation rather than simply lowering shelf temperature.

Recommended Actions

1. Extend hold time at nucleation temperature.

2. Deep freeze below -40°C after nucleation is complete.

3. Reduce aggressive annealing conditions.

4. Consider controlled nucleation technology.

5. Compare early-loaded and late-loaded samples.