Pipet washing validation

[Consumer Products Guy]

QA had us institute a classware cleaning validation SOP a year ago. Now QA wants us to initiate something to verifiy that our glass volumetric pipets are clean, to comply with cGMP. Does anyone do this already, or have any information they could share?

This type of information might help us to write an SOP (I know no one will want to "donate" their own SOP for this). Thanks.

[JGK]

You could just institute a review process:

How many blank samples are contaninated in say a 3-month period?

How many of the above contamination issues were traceable to a contaminated or supposedly clean pipette?

[tom jupille]

Shouldn't that be subsumed into system suitability? Run a blank and if no peak shows larger than LOD, then it's suitable for the purpose.

[Consumer Products Guy]

We have some sample formulations dissolved in water which leave a residue in glass pipets, so subsequent uses result in about 10 trapped bubbles of liquid in the pipet barrel which do not come out. This happens even with quick rinse out with solvent such as alcohol or acetone before the pipet wash, on the second and later use of brand-new volumetric pipets. This is why I feel that the electronic 5 ml pipetter would be more accurate in this case, and more efficient, but supervisor says we MUST first have a daily electronic pipet calibration check before using those...why I posted that topic....so it's not blank contamination I'm concerned about, it's delivering only (guess) 98% of the sample solution volume or standard solution volume when such glass volumetric pipets are used next time.

[Peter Apps]

I know I keep going on about weighing rather than measuring volumes - but this might just be a case where putting the sample container on a top loading balance might be the way to go.

Peter

[unmgvar]

QC of the QC should be done with the same rules used to QC what yo do.
statistical risk assessment and common sense is what is needed here.
in pharma, a batch of several hundreds thousands pills even million pills are released upon sampling barely a few hundreds and checking less then a hundred for release.
not by checking every pill

risk asses your situation
what is the cause of this? which product of your formualtion? is it because of big left over stuff in the pipet?
would filtering before be better for you to validate in the method?
maybe centrifuge?
too much time consuming, not helping anyway?
then back to what does it? know this then know how to clean it
introduce a SOP of wash for this situation,
you already know how to check when it does not happen, because you know what happens when it is not cleaned.
there will not be around 10 trapped bubbles of liquids that do not come out if cleaning procedure works

show that you have trained your analysts and they know that such a behavior if possible in your lab and they need to pay attention to it and take measures if they see it

[DR]

We have some sample formulations dissolved in water which leave a residue in glass pipets, so subsequent uses result in about 10 trapped bubbles of liquid in the pipet barrel which do not come out...

Pretty much our problem from time to tome too.
Validating the wash procedure also presumes that you will revalidate it for every subsequent new product or pipet using procedure to come down the pike. It's a training issue, I think. Chemists should catch when this happens and redo that dilution. If it happens regularly, then it is time to revisit either training on the procedure or the procedure itself.

We don't have a validated pipet cleaning procedure nor would I want to try to validate one. And yes (Tom), system blanks would be a part of it (if you actually take the trouble to prepare a blank dilution with a pipet - I've never seen it done).