Use of Working standard

[Sunjay]

Dear All,

We haev prepared a working std for Zolpidem Tartrate. The BP method for it is by potentiometer. So we have done the assay in triplicate (as per our SOP for working standard) by potentiometer titration.

Our formulation product assay is by HPLC (our in-house method for drug product).

So we have to use the Zolpidem Tartrate working standard for this and the potency is determined by non-specific method like potentiomenter.

My question is :
CAN WE USE THIS POTENCY OF WORKING STANDARD (DETERMINED BY POTENTIOMETRIC TITRAATION) FOR THE ASSAY OF DRUG PRODUCT BY HPLC METHOD?

or WILL THIS BE ACCEPTABLE TO REGULATORY ?
or WHAT CAN BE DONE IN THIS CASE?

Please guide me with your valuable inputs.

Warm Regards

[rc_12321]

SUNJAY, Since you have evaluated your working standard as per BP METHOD you can use it for your product irrespective of methods of analysis youhave choosen to analyse your product.

Depending upon the forumalation differences one may choose different methods to evaluate his product.I think either EP or BP does not state that same method of procedure should be followed for both API and Drug product.

May be potentiometric is most suitable method for analysing API hence BP mentioned about it.But your product formulation may be best analysed by HPLC .If you can convience the regulatory body ,it well accepted.

In my opinion methods to evaluate working standards(API) may be different to estimate the potency more accurately and same methods may not be effective for your formulation.