Polyvinyl Alcohol (PVA) assay

[michaelcarolus]

Hi All

I'm busy testing for PVA, in an eyedrop formulation, using a UV method. Our current method uses a USP reference std as a std. The USP std does not have a potency and therefore, the lab have assumed the potency to be 100%. When we use the USP std we always obtain assay values of +- 115% LC. I don't think this is correct, as there are various grades of PVA available. Should we not be using a std with a known assay value? Sigma-Aldrich have a few different grades of PVA e.g 87 - 89%.

Regards
Mike

[h4himel]

Plz let me know how do we know the potency and assay method of polyvinyl alcohol by HPLC or UV as different types of grades are available.
How can we develop an authentic method of polyvinyl alcohol assay?

[Consumer Products Guy]

I'm busy testing for PVA, in an eyedrop formulation, using a UV method. Our current method uses a USP reference std as a std.

How do you KNOW that the USP PVA standard has the same PVA distribution as the PVA from your supplier that's used in your product? I think I'd contact the supplier and pursue getting a certified standard from them that is the same homolog distribution.