PeptideMeter result on a Zhuhai dulaglutide lot lands 3.7 points above the supplier’s stated figure

PeptideMeter has released a batch of 15 analytical reports on research-grade dulaglutide lots, including material from BCH and JEEP. 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.

Reported figures across the set were: highest 95.4%, lowest 91.9%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 15 of them stated an integration threshold. The Journal has asked the laboratory to publish thresholds on all reports as a matter of routine.

Batch variance rather than vendor quality is the recurring finding of this programme. Across the 15 determinations the Journal has commissioned to date, within-vendor spread has been wider than between-vendor spread for two thirds of the companies tracked, which is an argument against rating any supplier on a single number.

"The useful thing in that report is not the percentage, it is the system suitability data," said Marek Doležal, analytical chemist and former QC laboratory manager. "It is the only part that tells you whether the percentage means anything."

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.