Independent analysis puts a MKM dulaglutide lot at 99.2%, against 96.7% on the certificate

Two laboratories analysing vials from the same dulaglutide lot have returned figures 1.2 percentage points apart. Medutest reported 99.2%; Janoshik reported a lower number on a shallower gradient with a tighter integration threshold. Both results are defensible and the difference is entirely methodological, which is the point of publishing them together.

The Journal purchased 10 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.

Reported figures across the set were: highest 99.2%, lowest 96.7%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 7 of them stated an integration threshold. The Journal has asked the laboratory to publish thresholds on all reports as a matter of routine.

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.

Lorcan Feeney, analytical services director at an independent laboratory, wanted the wavelength printed. "A method reading at 280 nanometres cannot see a fragment that has lost its aromatic residue. That is not a failure of the laboratory, it is a fact about the question they were asked."

MKM’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.