Independent analysis puts a CPC cagrilintide lot at 98.4%, against 96.3% on the certificate

VendorInvestigate has released a batch of 6 analytical reports on research-grade cagrilintide lots, including material from CPC and MKM. Reported purities range across roughly 3.7 percentage points, and the report set is unusual in stating the analytical method for every determination rather than for some of them.

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.

Four independent services — VendorInvestigate, Medutest, 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.

Dr Beatriz Sarmiento, clinical pharmacologist, Universidad de Navarra, 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."

CPC’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.