Custody, condition and the temperature nobody logged
A result on one vial generalises to a batch only if the vial was drawn in a way that makes it representative — and nobody records how it was drawn.
Testing Dispatch
Independent analysis puts a WWB exenatide lot at 98.5%, against 96.6% on the certificate
The result is unremarkable. What the report states alongside it is not.
An independent purity determination on exenatide material sold by WWB has returned 98.5%, a figure 1.5 percentage points above the number printed on the accompanying certificate, which the supplier had reported against a shorter gradient and a tighter threshold. The analysis was performed by PeptideMeter on a vial the Journal bought as an ordinary retail customer in February 2025 and posted unopened.
The Journal purchased 8 vials from the same lot at retail and had four 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.
Batch variance rather than vendor quality is the recurring finding of this programme. Across the 11 determinations the Journal has commissioned to date, within-vendor spread has been wider than between-vendor spread for two thirds of the companies tracked, which is an argument against rating any supplier on a single number.
Marek Doležal, analytical chemist and former QC laboratory manager, thought the split-sample design was the useful part. "A single result on a single vial is an anecdote with a decimal point. Pairs from one lot to two laboratories is the cheapest experiment that answers a real question."WWB’s dossier has been updated with this determination and with the company’s response to it. The dossier’s ordering box records the lead times, the minimum quantities and what a buyer should ask for at the point of order.
Related coverage
The badge is about a sample. The listing is about a product.
A badge asserts that something was tested. It does not assert what, when, on whose sample, by what method, or whether the lot on sale is the lot that was tested.
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The badge is about a sample. The listing is about a product.
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Retest date, expiry date, and the two conventions being confused
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