Lyophilization states are the different phases that a substance undergoes during the freeze-drying process, also known as lyophilization. These states reflect the physical and chemical changes that occur as the substance is frozen, dried, and preserved through the removal of water under vacuum conditions.
The first state in lyophilization is the frozen state, where the substance is solidified at ultra-low temperatures. During freezing, water molecules within the substance form ice crystals, immobilizing them within the matrix. This phase is critical for minimizing damage to the substance and preparing it for the subsequent drying process.
The next state is the dried state, which occurs as water is removed from the frozen material through sublimation under vacuum conditions. Sublimation involves the direct transition of water molecules from solid to vapor phase, bypassing the liquid phase. This process preserves the structure and integrity of the substance while effectively removing water, resulting in a dried product with minimal damage or degradation.
Finally, the lyophilized state refers to the end product of the lyophilization process, where the substance is stabilized and preserved in a dried form. Lyophilized products typically have a low moisture content and are resistant to degradation, making them suitable for long-term storage and transportation.