Freeze-drying

Freeze-drying is a low temperature drying process employed to convert (heat-) labile aqueous solutions into solids of sufficient stability.  Lyophilization is traditionally performed as a batch-wise process and is inherent related to several disadvantages like batch-to-batch variations and long process times. Our lab developed in collaboration with the Laboratory of Pharmaceutical Process Analytical Technology a continuous freeze-drying process. This continuous freeze-drying concept is based on spinning the vials during freezing (I.e. spin-freezing) and on non-contact energy transfer via infrared radiation during drying. This improves process efficiency and product uniformity compared to conventional batch drying. Our research focus is development of a formulation strategy and optimisation of the models used in the different steps of continuous freeze-drying.

Figure: Batch freeze-dried products