cleaning validation

hi all,
During start up of cleaning validation of tank, do i need to take sample of rinsate from every location (bottom, sample valve) or only one sample from random location is acceptable ?
Do i need to take sample for rinsate and swab together or only one among these will sufficient for cleaning validation. What are the initial aspects to be considered before starting cleaning validation.
Thanks in advance,

Dear prashant.chawla,

generally speaking, taking only one sample from a random location is unacceptable unless you could demonstrate that the residues are spread over the tank truly homogeneously. Actually, the locations where you sample in the tank need to be carefully chosen, in order to be worst case locations or be representative for bigger surfaces.

Regarding the sampling method, taking a sample from the last rinsate is normally not a choice for the cleaning validation (if you were sure, and could demonstrate, that all the contamination remaining in the tank goes into the last rinsate, you wouldn’t need a cleaning validation!), it would only be useful if you could correlate the level of contamination in the rinsate and the remaining contamination in the tank, for routine monitoring purposes. Usually you can sample by swabbing or rinsing with an appropriate solvent (which in most cases is not the solvent of the last rinse), each has advantages and disadvantages. Obviuosly, it is not possible to sample the same location by both methods, because with the first sampling you took away the contamination, and in the second sampling you won’t find anything.

Regarding the initial aspects before starting cleaning validation, i suggest to browse this forum, there are plenty of hints on how to start. If after that you need further assistance, you may post a more specific query.

Best regards