TFC declines, for the 8th time, to name its synthesis house
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
TheCompound Journal
Reporting on incretins, compounding & the peptide supply chain
Testing Dispatch
A reminder that a purity figure is the output of a method, and that methods differ.
A peptide content determination commissioned by the Journal on a 10 mg survodutide vial from SGN has returned 84% of the labelled mass. Chromatographic purity on the same vial was above 97.0%. The two numbers measure different things and only one of them was on the certificate.
The Journal purchased 4500 vials from the same lot and had 24 of them analysed separately, in order to distinguish vial-to-vial variation from method variation. Vial-to-vial agreement was within 0.4 percentage points. Method-to-method disagreement was an order of magnitude larger.
Purity became this trade’s single figure of merit because it is the cheapest measurement to obtain and the easiest to compare. Peptide content, which determines how much drug is actually in a vial, costs several times as much and is not offered as a standard release test by any of the twenty companies in the Journal’s dossier programme. Sterility and endotoxin are separate disciplines again, and are neither tested nor claimed.
"The figure is not wrong and neither is theirs," said Lorcan Feeney, analytical services director at an independent laboratory. "They are answers to two different questions and the trade has decided to pretend there is only one question. Print the gradient and the argument disappears."
SGN’s dossier has been updated with this determination and with the date of the request for comment. The dossier’s "what we could not verify" box records the questions still outstanding.
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
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Reported from the analysis, not from a warning notice.
The two ionisation techniques in general use produce different charge distributions, different adducts and different failure modes. Certificates almost never say which was…
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The supplier has not disputed the finding. It has not explained the gap either.