Hi everybody

I'm busy updating our method validation procedure and would like some advice on "method re-validation." What changes to a method are deemed significant and to what extend can changes be made.eg. If the mobile phase is changed from 80:20 to 90:10 MEOH/H2O is re-validation required although the method with the "new" mobile phase still meets all system suitability criteria. I read an article a while back (I think it was in the Pharmaceutical Technology mag),which addressed some of the changes that could be made to a method before it required re-validation. Unfortunately I can't seem to trace this article and I need some reference to support my procedure. Any help will be greatly appreciated.
Thanks

Download from Agilent an electronic seminar titled "Validated HPLC Methods - To Tweak or Not To Tweak" which lists variables that can be adjusted without re-validating. To my knowledge, there have been recommendations published but nothing is "official". I would also document on some samples that the results agree, and place in your files.

Anonymous,
why dont you just put an hyperlink in your text? That will spare a lot of searching work for everybody!

I would if I knew how - I'm a chromatographer first, not so good on these computer machines...is this what you mean?

http://webshop.chem.agilent.com/iccdocs/pubDocument.shtml

http://webshop.chem.agilent.com/icc/attendee/login?oldurl=/iccdocs/attendee/archive.shtml

If you read USP621 in the USP and PF you will find the exact recommendations for you question.

Also EP, chapter 2.2.46, gives you the limits of the adjustments that can be made to the chromatographic methods of the monographs.

Hi guys

Thanks for the quick response. I'm sure that the
above references will not only help me but alot of chromatographers out there.
Thanks once again.
Mike