Lyophilisation (or freeze drying) is the preferred process used by the pharmaceutical industry to preserve pharmaceutical products with minimum disruption to their formulation and preserve quality, while substantially increasing shelf life.
Lyophilisation works by freezing the material, and then reducing the surrounding pressure and adding enough heat to allow the frozen water in the material to sublime directly from the solid phase to the gas phase. Lyophilised products can be reconstituted quickly and easily, which is important for medical application.
However, pharmaceutical quality control and validation places significant demands on process reproducibility and product uniformity. New product formulations are increasingly putting more rigorous demands on the low temperatures and cooling rates that are crucial to the process.
Freeze drying is essentially a batch operation with complex cycles lasting for several hours or more, but until now technology has been limited when it comes to thermal control of the shelves and condensers of pharmaceutical freeze dryers, both integral components in the two-step lyophilisation process.
... to continue reading you must be subscribed
