Analytical methods Cleaning Validation

In order for the analytical testing of the cleaning validation samples (swabs or
rinses) to yield meaningful results, the analytical methods used should be
validated. This should be documented.
The basic requirements are:
· The ability to detect the target substance(s) at levels consistent with the
acceptance criteria
· The ability to detect the target substance(s) in the presence of other
materials that may also be present in the sample (selectivity)
(Companies might want to consider the following:
Where more than one impurity is suspected (which is probably the normal
case in API manufacturing) a method could be proposed that is not
necessarily specific for each of the impurities but detects them all
together. Then additionally the assumption must be made, that the worst
case (e.g. most active) impurity represents the whole residue. This is
secure approach for the patients and could be accepted by the authorities.
It is also an practicable approach for the industry because such methods
are for example dry residue determination for non volatile impurities or
TOC determination for water rinses, which are very simple methods. )
· The analytical method should include a calculation to convert the amount
of residue detected in the sample to 100% if the recovery data generated
indicates a recovery outside of an allowed range.
· Stability of samples over time if the time interval between removal and
testing of samples potentially effects sample integrity.