LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure
We submitted vials for endotoxin determination and report the results, the method and the laboratory, because a pyrogen figure without a method is as empty as a purity…
TheCompound Journal
Reporting on incretins, compounding & the peptide supply chain
Testing Dispatch
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
An independent purity determination on liraglutide material sold by WWB has returned 98.2%, a figure 4.1 percentage points below the number printed on the accompanying certificate. The analysis was performed by PeptideMeter on a vial the Journal bought as an ordinary retail customer in February 2024 and posted unopened.
The Journal purchased 1200 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.
The Journal purchased 1200 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.
Yusuf Kandemir, freight and customs broker, Istanbul, 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."
WWB’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.
We submitted vials for endotoxin determination and report the results, the method and the laboratory, because a pyrogen figure without a method is as empty as a purity…
Storage instructions in this market are close to uniform and almost never accompanied by the study that would justify them. Uniformity is a sign of convention, not of…
Reported from the analysis, not from a warning notice.
The result is unremarkable. What the report omits is not.
The report states the gradient, the wavelength and the integration threshold, which is more than most.
We asked twenty companies three questions about stability data and print every answer, refusal and non-response.