6. Conclusion

Freeze-drying is a technology based on fundamental principles of phase transformation and heat and mass transfer. Understanding these principles is necessary to optimize the various stages of a freeze-drying cycle in a non-empirical way, in order to develop efficient freeze-drying cycles. The numerous studies carried out on the phase transformations involved in a freeze-drying cycle (crystallization and sublimation of ice, vitrification of the supersaturated water-solute solution) have led to significant advances in the programming of an operating mode. These advances are also the result of technological development in the field of sensors, used to monitor crucial parameters (product temperature, chamber pressure) in situ during a cycle. Sustained activity in these scientific and technological fields should lead to improved optimization of freeze-drying procedures. The biopharmaceutical...