PeptideMeter result on a Tianjin liraglutide lot lands 4.0 points above the supplier’s stated figure

PeptideMeter has published a purity determination of 99.4% on a 2 mg vial of liraglutide supplied by TFC, against a figure of 95.5% on the certificate that accompanied the vial. The sample was submitted by the Journal in February 2026 as part of a continuing programme of arm’s-length purchasing, and the vendor was told before the order was placed that any result would be published.

Content by elemental nitrogen determination returned 99% of the labelled nominal mass, which on a 2 mg vial corresponds to roughly 11.78 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.

Content by elemental nitrogen determination returned 99% of the labelled nominal mass, which on a 2 mg vial corresponds to roughly 11.78 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.

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.

Marek Doležal, analytical chemist and former QC laboratory manager, 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."

TFC’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.