The specificity and the sensitivity of the method used for detection of contaminants after cleaning process are of great importance.
If the residues of previous product or the cleaning process is not detected in the analysis, which doesn’t mean that it is completely absent, it may be a case where the sensitivity of the analytical method and the limits may not be able to trace them in present concentration in the sample. The poor sampling method may be a cause of the absence of residue after cleaning as well. Therefore it is advisable that the analytical method must be challenged with different combination of sampling methods which are particularly used to demonstrate that the contaminant residue can be removed from an equipment surface at the level of 50% and 90% etc .
Cleaning process evaluation and production in process quality control tests.
In process quality assurance tests can be used as tools to evaluate the efficacy of cleaning process, some of the indirect test like conductivity of last wash water can be used to predict and monitor the cleaning process. There must be a correlation between the in process test used to monitor effectiveness of cleaning, and during validation these tests should document that the the equipment not cleaned completely fail the in process tests employed. good manufacturing practices
Test for Total Organic Carbon (TOC) (TC ) for evaluation of efficacy of cleaning process: