Determination of Primary Drying End Point...

Determination of Primary Drying End Point...

Release Date: January 06, 2010

Freeze drying is the process of drying a product in a frozen state under vacuum to increase product stability, minimize the effects of oxidation and degradation, and increase the shelf-life of the product. The process has found application for preserving products including biologicals, bacterial cultures, water-damaged documents, tissue preparations, food and therapeutic products such as vaccines, drugs, antibodies and proteins.  A critical point in the freeze drying process is when the last drop of solvent has been removed from the sample - the primary drying end point.

There are two types of vacuum gauges/sensors that are routinely used in modern pilot scale and production freeze drying and lyophilisation equipment. The technical note describes how capacitance manometers and Pirani vacuum gauges work as well as detailing their operational advantages and disadvantages. By taking convergence data from a freeze dryer equipped with both capacitance manometer and Pirani gauge sensors the authors demonstrate a reliable technique for accurately determining the primary drying end point.

A copy of the new technical note is available from Tech Briefs

SP Industries is a leading manufacturer of laboratory to production scale freeze dryers / lyophilizers, centrifugal evaporators and concentrators, environmental control chambers, thermal control system, glassware washers and dryers. The company sells its products under well-known brands including Hotpack®, VirTis®, FTS™ and Genevac®. SP Industries has ISO 9001:2000 registered production facilities in the USA and Europe.  

For further information on primary end point determination contact SP industries on +1.845.687.5315 (+44-1473-240000 in Europe) or email 

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