Independent analysis puts a WWB survodutide lot at 99.2%, against 95.5% on the certificate

A peptide content determination commissioned by the Journal on a 30 mg survodutide vial from WWB has returned 86% of the labelled mass. Chromatographic purity on the same vial was above 99.2%. The two numbers measure different things and only one of them was on the certificate.

The Journal purchased 3400 vials from the same lot and had 5 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.

Batch variance rather than vendor quality is the recurring finding of this programme. Across the 5 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 Yusuf Kandemir, freight and customs broker, Istanbul. "It is the only part that tells you whether the percentage means anything."

WWB’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.