Peak Purity for Analyte in Standard & Placebo Spiked

[gtma]

For specificity, peak purity is commonly evaluated for aged/fresh drug product sample(s). Is there a requirement to evaluate peak purity for the main analyte(s) in the standard and placebo spiked as well?

[adam]

There is no requirement. But it's not a bad idea to run it for the standard, just to see if there could be a process impurity hiding underneath the main peak.

We usually run peak purity on standards, unstressed samples, and stressed samples. Our acceptance criteria only applies to the stressed samples, but the others provide some useful information.