By raman on Friday, July 30, 2004 - 02:57 am:

Hello friends,

I developped an HPLC method for a product and tested the samples. And validated. Then studied the forced degradation. I found peak purity of the compound and all the impurities are resolved. For the same product pharmacopeia has given method and I tested and compared. The results are same.
Recently I received a method from our customer and with this method he and we got an impurity of about0.5% level,for which I am not able to justify.
Can anybody clarify which method I have to follow.

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By David Blais on Friday, July 30, 2004 - 05:46 am:

Raman,

My suggestion would be to use whichever method is required for testing in the product specification sheet.

As for the impurity at 0.5%, is this a peak from the drug substance? Or is it simply from the sample matrix?

Regards,
David

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By Bob Boberson on Thursday, August 5, 2004 - 12:39 pm:

Raman,

There is always a better LC method out there. Unfortunatley we could spend years finding the best one. I would always follow the USP because they validate it at their house which means your don't have to have your validation of the method audited, just a method verification and training according to your internal SOP's.

If a customer insists you use there method and it is validated than it might be easier to follow their method.

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By Raman on Wednesday, August 18, 2004 - 04:56 am:

Thank you Mr. David and Mr. Bob