(unofficial) video commentary : Lyophilization is a process containing two phases : freezing and deshydratation. Freezing is important because it define the quantity of water that will be taken out of the product. Deshydratation comprehend two phases : sublimation (from liquid to gaz phase directly, with an enthalpic variation of both fusion(333) and evaporation(2501) so 2834 kj/kg) and then desorption (removal of solvent molecule from a substance i.e. drying) 0:23 Load : the pressure is atmospherical and temperature ambiant (the door has been opened to load in the first chamber) The second chamber, containing the ice trap, is closed. 0:30 Freezing : T goes to -50, -60°C in order to turn into ice the water of the product. 0:44 Primary drying : the water easiest to reach is sublimated. To do that, the pressure reduce to around 1mbar and the temperature rise to 5°C (from conduction thanks to the support and from radiation thanks to the metal tubes), to ensure that the water is below the triple mixt point (see phases diagram of water) and that the ice is turned directly into vapour. The ice-trap chamber is opened and the air flow make sure that the vapour go towards the cold tubes, which accumulate ice. Note that the water is taken out of the product at 5°C so the product is suitable for thermolabile compounds (sensitive to T like vitamins) 1:23 Secondary drying : If you follow the phases diagram, the idea here is to go lower in P and higher in T to convert as much water as possible in the vapour state. This secondary cycle has 0.01mbar and 20°C for exemple and is used to take out a supplementary amount of water that is harder to get (deeper in the matrix of the product) nb : another drying cycle may be conducted to minimise the quantity of water content in the product and ensure that it will not have any microbial or chemical activity 1:55 At equilibrium, the ice-trap chamber is closed, the pressure return to normal (otherwise you cannot seal the vials and they would be very hard to open) and the vial are sealed. 2:02 Between each cycle the ice-trap is emptied to maximize its efficiency. It takes a few hours to melt the ice back naturally or the process can be faster with the injection of hot steam. I imagine hydrogen peroxyde is used to sterilize the chamber
I presume this not to be true as it is not directly heated but the latent, solvent-specific heat is added in order to lyophilise the vials content. The last steps are only made in order to sterilise the machine as this is a pharmaceutical device. Interesting is, that this device appears incapable of sterilising the device concerning specific bacteria as for instance those which trigger the new creutzfeldt-jacobs desease. The temperature of 126 degree celsius is too low to destroy aforesaid bacteria
NoahCue Creutzfeldt-Jacobs disease is not caused by bacteria, but by so-called prions, which are proteins. Those are unlikely to be present in just about any and all pharmaceuticals that are freeze-dried. If they may be present, they should be removed through other means prior to the lyophilization step.
