Independent analysis puts a FGP exenatide lot at 96.3%, against 92.6% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
Testing Dispatch
Independent analysis puts a HJ dulaglutide lot at 95.0%, against 93.3% on the certificate
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 5 mg dulaglutide vial from HJ has returned 87% of the labelled mass. Chromatographic purity on the same vial was above 95.0%. The two numbers measure different things and only one of them was on the certificate.
The Journal purchased 3400 vials from the same lot and had 14 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.
Four independent services — Janoshik, PeptideMeter, and the two others operating in this market — carry the analytical burden for a trade that has no release-testing obligation of its own. Each is paid by whoever submits the sample, which is usually the vendor. The Journal’s position is that a submitter-pays model is workable but that its incentive structure has to be stated whenever a result is quoted as verification.
"The figure is not wrong and neither is theirs," said Yusuf Kandemir, freight and customs broker, Istanbul. "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."
HJ’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.
Related coverage
PeptideMeter result on a Changsha liraglutide lot lands 3.8 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
VendorInvestigate result on a Guangzhou retatrutide lot lands 3.9 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Independent analysis puts a WXT exenatide lot at 97.4%, against 93.5% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
The retest date and the expiry date are not the same document
We asked twenty companies three questions about stability data and print every answer, refusal and non-response.
Sterility is not a percentage, which is the whole difficulty
Every certificate circulating in this market answers a question about molecules. Almost none answers a question about organisms, pyrogens, or the integrity of the seal.