Problems, Failures and Deviations

Possible problems during the operation of freeze-drying plants can mostly be assigned to four categories  

those requiring immediate, preferably automatic, action  

those to be corrected automatically or by hand within few minutes  

The analyses of problems and the required counteractions will depend on the operation principles of the operator, the value of a lyophilization charge, the sensitivity of the product to deviations from the set values and several other factors. Nevertheless, an analysis of possible problems and a guideline for counteractions should be established for every freeze-drying plant as part of the instruction manual, even if it has to be adjusted for new products. 

The following summary cannot be a complete list, and reflects only the more likely events causing trouble (in Section 6.1 several problems are discussed related to product structure, stoppers, traces of volatile components, etc.). 

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