Chromatography Forum

Hi All

I’m in the process of developing and validating methods for a finished product that contains the following substances:
Naphazoline HCl - HPLC – UV Detector
Polysorbate 80 - HPLC – ELS Detector
Hypromellose - HPLC – ELS Detector
Polyaminopropyl biguanide - HPLC – ELS Detector
Zinc sulphate - AA
Disodium edentate - HPLC – UV Detector

The methods will be used for stability testing. Would I be required to perform forced degradation studies on all of the above methods? How would you prove "peak purity" when using a ELS detector?

Many Thanks
Mike

How would you prove "peak purity" when using a ELS detector?

You couldn't. That's an almost universal detector (for non-volatiles) with no selectivity whatever.

Do you really have to test all that excipients stuff in your final product??

Unfortunately we have too. It is stated on the label with the various concentrations.

Michaelcarolus, this is the first time i heard that all excipients are assayed for the finish product. Are u really sure that these results are required?

To my opinion there is no need for forced degradation except naphazoline.

As Tom stated there is no way for peak purity in ELSD.

Michaelcarolus, this is the first time i heard that all excipients are assayed for the finish product. Are u really sure that these results are required?

To my opinion there is no need for forced degradation except naphazoline.

Full ACK. That's what I was aiming at.

Hi All

I’m in the process of developing and validating methods for a finished product that contains the following substances:
Naphazoline HCl - HPLC – UV Detector
Polysorbate 80 - HPLC – ELS Detector
Hypromellose - HPLC – ELS Detector
Polyaminopropyl biguanide - HPLC – ELS Detector
Zinc sulphate - AA
Disodium edentate - HPLC – UV Detector

The methods will be used for stability testing. Would I be required to perform forced degradation studies on all of the above methods? How would you prove "peak purity" when using a ELS detector?

Many Thanks
Mike

Hey mike,
Like you I have to report three of these excipients too. I am trying to perform a force degradation study for a stability indicating method (validation) for Polysarbate 80, Hypromellose and biguanide. Any success in degrading this polymers?..what about dissolving them in 60% organic, or T= 100C ?... they are indestructible .-). I am using a LC-GPC-RI system. Please let me know.
Thanks
Carlos
Email: cjsaca@gmail.com

Only Naphazoline HCl should be subject to forced degradation. Zinc sulfate is inorganic how would you study its forced degradation? it will degrade into what?
What you can study is the interaction between every excipient and your API.

Hi All

Thanks for the all the comments. We will only do forced degs on the Naphazoline HCl.

Regards