Impurities in DS and DP

[Kina83]

Hello everyone,

I have an HPLC method for the analysis of impurities in API, do you think I can use the same method for the analysis of impurities and degradation products in Drug Product?

Thank you very much in advance

[vmu]

It depends on the composition of the particular drug product. Maybe you can, maybe you can't.

[Kina83]

And where to start? How to know what impurities can be generated? Can there be different impurities in the API than in the final product? How to fulfill the lCH? Thanks so much for any help

[vmu]

And where to start? How to know what impurities can be generated? Can there be different impurities in the API than in the final product? How to fulfill the lCH? Thanks so much for any help

The impurities originating from the API (API related compounds) in the drug product are usually the same as they are in the API. However, a few new API related compounds can result form the drug manufacturing process (additional treatment of the API in a mixture with excipients can lead to new degradation products). This is one side of the problem.

The other (usually the main) side of the problem is to develop the analysis method with sufficient selectivity. For an API, it is sufficient to separate the main compound and its impurities. For a drug product, it is also necessary to separate the excipients from the compounds of interest.

[tom jupille]

To elaborate a bit on vmu's reply:
- you will have to fully validate the new method.

Your existing method may provide a starting point. You could run the existing method on the API, on a placebo (final product minus the API) and on the final product and look for differences. That should give you some idea what you are up against.