Below specification Iron Assay

Validation
1

The formulation contains Moringa extract and Iron (as Ferrous Sulfate Heptahydrate). During the assay using the AAS method, the final product (FG) result for iron is below specification, approximately 78-88%, with or without Moringa extract. However, using the titration method, the raw material alone meets specifications, but as a final product, the iron content exceeds specifications. What could be the reason for this

2

Please verify following aspects about the calculation of iron content by both the methods (AAS and Volumetric titration method,

  • Have you added the amount of Ferrous Sulphate hepta hydrate considering 7 molecules of water of crystallization (FeSO4.7H2O) ? And while calculating through AAS method have you considered this water of crystallization in the molecular weight or NOT?
  • Similarly for the volumetric titration method exactly what molecular weight of Iron salt is considered? With OR without 7H20 ?
  • The above aspects will considerably change the analytical results and hence Iron content in the final product.
  • This means have you considered 1Fe (Iron atom) = FeSO4.7H20 OR only FeSO4. You must consider the same (either with 7H20 OR without 7H20) at all places means, when adding this iron salt into the final product and doing the analytical calculations by both analytical methods.
    Please confirm these aspects.
3

We consistently use ferrous sulfate heptahydrate in our computations because it’s the ingredient added to the product. We convert it to iron to determine the iron content, but we’re struggling to get an assay within specification and are unsure of how to proceed.

4

Thanks for your feedback.
Please share details of calculations used for both analytical methods.
Also please share how much quantity of FeSO4.7H2O is added in the final product and the labeled amount of Iron in the final product. (mg of Iron per tablet or capsule or 100 g of powder.

5

Hi,

Attached are the computations of the assay results using the titration method. For the AAS method, I can only provide the results as it was tested by a third party, given our lab’s lack of capability. In the titration method, the results are within specification for the sample without Moringa extract. However, with Moringa extract, the endpoint cannot be detected due to the green color of both the endpoint and the Moringa extract.

6

I can’t attach the media. I don’t know why.

7

I could not see any computations of the assay results by titration method. Please send the same.

8