Independent analysis puts a BCH cagrilintide lot at 96.6%, against 93.4% on the certificate

An independent purity determination on cagrilintide material sold by BCH has returned 96.6%, a figure 3.5 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 Janoshik on a vial the Journal bought as an ordinary retail customer in January 2024 and posted unopened.

Content by elemental nitrogen determination returned 98% of the labelled nominal mass, which on a 5 mg vial corresponds to roughly 10.27 mg of peptide rather than the labelled figure. The remainder is accounted for by counter-ion, residual water and residual solvent, none of which is visible chromatographically.

The Journal purchased 12 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.

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 quoted as a priced addition by most of the twenty companies in the Journal’s dossier programme rather than carried as a standard release test. Sterility and endotoxin are separate disciplines again, and are neither tested nor claimed.

"The gap that matters is not between the two laboratories, it is between either of them and the certificate," said Havel Novotný, independent laboratory quality manager. "One of those documents states a method. Compare like with like and most of this disappears."

BCH’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.