Validation Rinse Sampling


I have a question concerning rinse sampling validation. In our company it is not possible to rinse the process equipment for method validation. How can we perform it in lab scale using small containers. Is there any papers, method descriptions available.
Is it neccessary to validate this method? We do not find any informations?

Thanks for your help


first of all differentiate between rinse sampling (sampling the last rinsewater and seek for contamination) and sampling by rinsing (that is, instead of swabbing, rinsing the equipment or parts of it with an appropriate solvent). The only accepted one is the latter, and I guess it is what you want to do. The same as for swab sampling, method validation is a requirement.

There are not many papers about this, I recommend the cleaning memos from Destin LeBlanc (issued monthly, the ones from the current year are free on his website
, the older ones can be purchased. The October 2002 issue is about recovery studies for rinse sampling). The key issue is the recovery test, and there are two cases: 1- The surface type does not allow swab sampling (perforated sheets, mesh sieves, etc.), 2- The sampled surface is not accessible for swab sampling (hoses, pipes, dosing pumps, etc). In the first case, try to get samples of the surfaces from the manufacturer of the equipment, in the second case the recovery test has to be performed in the equipment itself (by the way, how is it that you cannot rinse the production equipment for method validation, if later you will have to do it at least three times for the cleaning validation itself?). In any case, both the solvent amount (0,5 - 1 ml/cm² is a good starting point) and the rinsing method have to be validated and that is where I doubt you can run the recovery test in smaller containers, because it is difficult to prove that the rinsing is performed in exactly the same way.

Hope this clarifies a little bit.

Best regards