Independent analysis puts a WWB exenatide lot at 97.8%, against 95.3% on the certificate

Janoshik has released a batch of 4 analytical reports on research-grade exenatide lots, including material from WWB and ERP. Reported purities range across roughly 1.7 percentage points, and the report set is unusual in stating the analytical method for every determination rather than for some of them.

The Journal purchased 12 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.

Discrepancies of one to two percentage points between a supplier’s figure and an independent determination are common and usually explicable: a faster gradient resolves fewer impurities, a higher integration threshold discards more small peaks, and a wider solvent-front exclusion window removes early-eluting fragments from the calculation altogether. None of that is misconduct. All of it is invisible unless the method is disclosed.

"Ask for the suitability summary before you argue about the percentage," said Lorcan Feeney, analytical services director at an independent laboratory. "If the tailing factor and the replicate precision are outside limits, you are arguing about arithmetic performed on an unfit separation."

WWB’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.