Secondary standard

Which method should be used when a secondary reference standard is re-calibrated against a primary reference standard? Should it be the USP and/or EP method for that API or should it be the finished product in-house method that the secondary standard is going to be used for? Must it be a stability indicating method?

If a secondary standard is calibrated or Re-calibrated using a USP primary reference standard, we can call it as secondary standard used in place of USP Reference standard.

If you want to use this secondary standard for EP Monograph, You should calibrate this standard against EP Reference standard.

If you want use it for In-house , if should be qualified like Primary reference standard(Specific identity tests like NMR, CHN Analysis, MASS, IR, UV etc…)

I hope this helps.

Regards,
Bujji Reddy.Kanchi

Thanks,

I want to use this standard in place of USP REF STD. My secondary standard will be used when I’m performing release analysis of a Product for the US market. But should the calibration of my secondary standard be done with the pharmacopeial methods for that API or should it be my in-house methods for the my Product?

[quote=QPAB]Thanks,

I want to use this standard in place of USP REF STD. My secondary standard will be used when I’m performing release analysis of a Product for the US market. But should the calibration of my secondary standard be done with the pharmacopeial methods for that API or should it be my in-house methods for the my Product?[/quote]

You should use Drug substance method whether In house or USP to qualify Secondary standard against Primary standard.

Yes, It should be qualified by using pharmacopeia methods only.

Regards,
Bujji Reddy.

If you have shown that your in-house method is equivalent or better than the applicable pharmacopeial method, you should be able to use your in-house method. However, you need to be confident of your method validation documentation and be able to stand behind it. If you have any doubts, using the pharmacopeia method is the safer option.

Hi everyone, i’ve a a simple question that you may help with…
If i like to prepare a secondary reference substance for hplc assay in finished product, what analisys may i have to perform to validate it?
is it valid only performing hplc analisys against primary reference? or may have to perform other analisys like IR, UV, water content i.e.?
thanks a lot in advance for you kind response.
Kind regards,
Fabian.

You will have to have an SOP on preparing and testing a secondary standard. I usually just purchase a 99% pure Sigma-Aldrich bottle that has already been analysed by UV, NMR, MS, FTIR…

You should also used a validated (ICH Q2) or USP verified (<1224>?) method.

Hi, in response to fabrids,
I suggest that every reference substance must be validate before use. As its used as reference to evaluate our product.
Qualify your working standard against reference standard by evaluating critical quality parameters like LOD/Water, Purity/Assay, IR & Impurity Profile/Related Substances with duplicate or triplicate analysis.