Freezing of many vials in a freeze dryer normally works out as a stochastic process. All vials will freeze only within a certain time frame, e.g. 1 hour. Furthermore, this crystallisation happens at different temperatures. Crystal structure and later drying behavior will diverge.
The new developed technology LyoCoN by Christ creates a controlled nucleation of all to be lyophilised vials: After loading of the machine, the cold ice condenser accumulates ice crystals (pict. 1). Simultaneously the liquid product is cooled down close to the freezing point. In the next step a slight vacuum is established in the freezedryer (pict. 2). The external recipient is kept under atmospheric pressure. Finally a pressure equilibration between recipient and freezedryer is started by opening a valve to the ice condenser. The air/gas from the recipient is injected into the ice condenser. The resulting ice fog infiltrates all vials (pict. 3). These crystal nuclei immediately start homogenious crystallisation in all vials.
After this, the freezedryer is aerated completely to atmospheric pressure. Freezing of all crystallized vials can be continued in a conventional way, e.g. further freezing down,
Martin Christ LyoCoN – facts at a glance:
At the push of a button initiated crytallisation of all vials inside the freezedryer.
LyoCoN-demonstration in a production unit Epsilon 2-65D.