Calculating %Assay for HPLC Stability Study

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In a stability study involving HPLC analysis, the main challenge is calculating the percentage assay for both the active ingredient and its degradants using the concentration range of formulations. The discussion highlights the importance of using a standard to determine concentration based on response factors. Key considerations include whether to analyze materials by peak height or peak area, the resolution of degradants from the active peak, and how response varies with concentration. It is crucial to ensure that the test material's peak height or area falls between the low and high concentrations of the standards for accurate results. There is an acknowledgment of confusion regarding these calculations, indicating a need for further research and clarification on the topic.
ChemiePham
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I am running a stability study and have assayed by HPLC my t=0 timepoint. I only have the range of concentrations for the formulations...how do I go about calculating the %assay for the active and degradants?

I ran a standard during the run and have calculated the concentration by based on my response factor but after that I am stuck...
 
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When you ran the study, did you obtain data? Are you analyzing your materials by peak height or by area? Are the degredants well resolved from your peak of interest? How does the response... either by peak area or peak ht., vary with concentration? Is the peak ht. or peak area of your test material between that of the low concentration and high concentration of your standards?
 
chemisttree said:
When you ran the study, did you obtain data? Are you analyzing your materials by peak height or by area? Are the degredants well resolved from your peak of interest? How does the response... either by peak area or peak ht., vary with concentration? Is the peak ht. or peak area of your test material between that of the low concentration and high concentration of your standards?

Hi,

I am really having a sort of confusion here and I think that I have to search about this little much, by far it is like a sort of question that I am some where thinking of as, please if you find some good knowledge about this then do let me know.


Thanks!
 
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