Quadrupole, time-of-flight, orbital trap: what each class can and cannot see
Parts per million sound impressive until they are converted into daltons at the molecular weight of the thing being measured.
Testing Dispatch
Independent analysis puts a JEEP semaglutide lot at 98.0%, against 96.9% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
A peptide content determination commissioned by the Journal on a 20 mg semaglutide vial from JEEP has returned 92% of the labelled mass. Chromatographic purity on the same vial was above 98.0%. The two numbers measure different things and only one of them was on the certificate.
The Journal purchased 500 vials from the same lot and had 3 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.
Havel Novotný, independent laboratory quality manager, was more cautious. "One lot tells you about one lot. I would not draw a conclusion about a company from a single determination, and I would not let a company draw one either."
JEEP’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
What a laboratory knows about the material it receives
Every third-party report in this market describes a sample somebody chose to send. That choice is outside the laboratory’s control and outside its records.
A percentage is not a specification
Chromatographic purity is cheap, fast and comparable-looking. Those three properties, and not its usefulness, explain why it became the industry’s single figure of merit.
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.
Independent analysis puts a GL Biochem liraglutide lot at 97.5%, against 93.6% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Independent analysis puts a TFC tirzepatide lot at 98.3%, against 95.4% on the certificate
The result is unremarkable. What the report omits is not.