HPLC method for ascorbic acid determination in a cream drug

[gnikol21]

Hi all
I want to dermine the content of ascorbic acid in a cream drug product. Can anyone share any HPLC method for doing this?
Thnx in advance

[Consumer Products Guy]

Do you have refractive index detector there? Conductivity detector? ELSD?

My mind-reading powers have long vanished....

[gnikol21]

I have an HPLC with RI detector.

[Consumer Products Guy]

I have an HPLC with RI detector.

OK. Now let us know if you're looking in the 100 ppm range, 1000 ppm range, 1% range, etc.

[Gerhard Kratz]

Cream means fat?? In that case, during sample preparation do ultra sonic and than store your sample in the freezer for 15 minutes, than centrifugate and it should be a clear liquid for injection.
Check application books of different manufacturers of HPLC columns. Good luck

[gnikol21]

Thnx Gerhard for your help i will try this extraction to check the recovery and i hope to be fast enough to prevent the degradation of ascorbic acid

[gnikol21]

well Im working in a range around 50ppm

[HippyLabRat]

For extraction solution/sample diluent I used 1% meta-phosphoric acid (HPO3 not H3PO4) in water. Sigma was the least expensive supplier I could find. I was using this for extracting multivitamins, and I was getting preservation on the order of about 5 days with about a 2% loss in concentration over that time.

Hope this helps.