Independent analysis puts a Homopeptide orforglipron lot at 99.1%, against 98.4% on the certificate

A peptide content determination commissioned by the Journal on a 30 mg orforglipron vial from Homopeptide has returned 87% of the labelled mass. Chromatographic purity on the same vial was above 99.1%. The two numbers measure different things and only one of them was on the certificate.

The Journal purchased 2200 vials from the same lot and had 13 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 99.1%, lowest 98.4%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 13 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 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.

"The figure is not wrong and neither is theirs," said Yusuf Kandemir, freight and customs broker, Istanbul. "They are answers to two different questions and the trade has decided to pretend there is only one question. Print the gradient and the argument disappears."

Homopeptide’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.