Lyophilization, commonly referred to as freeze drying, is the process of removing water from a product by sublimation and desorption. The freeze drying process is optimised by the introduction of solvents and gas species to improve product quality and to enhance the drying process.

Hiden's gas analysers provide detailed information about the gas/vapour composition during both the primary and secondary drying phases. Detection of the on-set of the secondary drying phase is readily detected. Analysis during the secondary drying phase enables a reduction in process cycle time and provides end point detection. Accurate determination of a user defined process 'end point' enables high consistency in product yield from batch to batch.