Chromatography Forum

Hi,

I am about to validate an ID test for a peptide drug and I have chosen to use a HILIC method.

All I have to do is to demonstrate specificity, but against what? I had planned to only use the placebo components, but I do not know if that is enough. Would you include degradation products and/or other APIs as well?

thanks,

Here is identification of drug products according to Q6A. You do not need to study degradaion products but you have to make identification according to standard and a closely related compond (maybe another peptide in your case) should be shown in your chromatogram (like many identification methods in Ph. Eu. Besides working on a PDA detector and showing the comparison of standard and sample spectra will be a plus.

Identification testing should establish the identity of the new drug substance(s) in the new drug product and should be able to discriminate between compounds of closely related structure which are likely to be present. Identity tests should be specific for the new drug substance, e.g., infrared spectroscopy. Identification solely by a single chromatographic retention time, for example, is not regarded as being specific. However, the use of two chromatographic procedures, where the separation is based on different principles, or combination of tests into a single procedure, such as HPLC/UV diode array, HPLC/MS, or GC/MS, is generally acceptable.

Thanks!

I have been down the diode-array track, but that is very unspecific for peptides (all have the same UV-spectrum). MS is not an option, since the QC lab does not have it.

Our standard approach is to mix a reference standard with the sample (50/50) and then show that the resulting main peak has "a size and shape corresponding to a pure reference standard". That is the method.

For the validation, I am still not sure what to use to demonstrate specificity. The company that produces the API for this drug manufactures a long list of other peptides. Cannot test all of them....

Thanks!

I have been down the diode-array track, but that is very unspecific for peptides (all have the same UV-spectrum). MS is not an option, since the QC lab does not have it.

Our standard approach is to mix a reference standard with the sample (50/50) and then show that the resulting main peak has "a size and shape corresponding to a pure reference standard". That is the method.

For the validation, I am still not sure what to use to demonstrate specificity. The company that produces the API for this drug manufactures a long list of other peptides. Cannot test all of them....

Mattias
Of course you cannot try all compounds for validation. If i were you i would select and try the most discriminative peptide (eg: close structure, functional group etc.) to show specificity.

Good luck