[brbabu_1979]

Hi every one,
                         We are using some chromatic method to evaluate the impurities of ’ X’ product. All the analytical methods were validated according to ICH and USP guidelines. We are receiving the API from ‘A’ source for ‘X’ product. Recently we changed the API from ‘B’ source.  The ‘B’ source chemical synthesis is different from ‘A’ source. Now my question is if we change the API source is there require to re-validate the chromatographic method again? Anyone can help me in this situation. If anybody having the information about the validation please forward to me. My mail ID is brbabu_1979@yahoo.com.   

Thanks in advance   
Babu

[sjb]

Under what conditions is your method from A valid?

[brbabu_1979]

Thank you sjb. But I don't understand your question. Please canyou elaborate that.

Babu

[JGK]

How pure are the API materials from sources A and B.

The API should be the API no matter what the source. the only variation may be in any impurities fro the syntessis.

A revalidation may not be neccessary if you can show that source B material is chromatographically indistinguishable from Source A material.

[sjb]

Imagine, for instance making a t-butyl ester from an acid and alcohol. In one case the t-butanol is made from from isobutene and HBr, followed by displacement; or in another case by oxidative cleavage of the olefin and then MeLi, with isobutene being the API, then the intermediates would be different, and have different properties which you may not be able to see in a method specifically developed for one or other route.

I would argue that you may very well need revalidation of your analysis.

[brbabu_1979]

Thanks JGK and sjb for your replays.
Mr sjb I agree with you. I also argue that revalidation is required. But is there any FDA or any regulatory guidelines says that we need to do validation. Please if you know that or if you have any guidelines please forward to me

Thanks
Babu

[JGK]

FDA draft Guidance http://www.labcompliance.de/documents/FDA/FDA-Others/Laboratory/f-505-method-validation-draft.pdf

Section 9 -Revalidation "When sponsors make changes in the analytical procedure, drug substance (e.g., route of synthesis), or drug product (e.g., composition), the changes may necessitate revalidation of the analytical procedures. Revalidation should be performed to ensure that the analytical procedure maintains its characteristics (e.g., specificity) and to demonstrate that the analytical procedure continues to ensure the identity, strength, quality, purity, and potency of the drug substance and drug product, and the bioavailability of the drug product. The degree of revalidation depends on the nature of the change.

When a different regulatory analytical procedure is substituted (e.g., HPLC for titration), the new  procedure should be validated (see section VII).

If during each use an analytical procedure can meet the established system suitability requirements only  with repeated adjustments to the operating conditions stated in the analytical procedure, the analytical procedure should be reevaluated, amended, and revalidated, as appropriate."

[brbabu_1979]

Thank you JGK and appreciated for your valuable replay.
Yes ICH Q2R1 also says the same.
Furthermore re-validation may be necessary in the following circumstances:
- changes in the synthesis of the drug substance;
- changes in the composition of the finished product;
- changes in the analytical procedure.
The degree of re-validation required depends on the nature of the changes. Certain other changes may require validation as well.

Now I am clear about the re validation. Thank you very much once again
 Thanks
Babu