Independent analysis puts a BCH mazdutide lot at 95.5%, against 94.0% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Testing Dispatch
Independent analysis puts a WXT tirzepatide lot at 96.4%, against 93.6% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Two laboratories analysing vials from the same tirzepatide lot have returned figures 3.5 percentage points apart. PeptideMeter reported 96.4%; Medutest reported a lower number on a shallower gradient with a tighter integration threshold. Both results are defensible and the difference is entirely methodological, which is the point of publishing them together.
Content by elemental nitrogen determination returned 87% of the labelled nominal mass, which on a 10 mg vial corresponds to roughly 7.54 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.
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 Yusuf Kandemir, freight and customs broker, Istanbul. "It is the only part that tells you whether the percentage means anything."
WXT’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.
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Documentation practice is the only part of vendor quality a buyer can assess before purchase.
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Janoshik result on a Nantong exenatide lot lands 3.1 points below the supplier’s figure
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The badge is about a sample. The listing is about a product.
A badge asserts that something was tested. It does not assert what, when, on whose sample, by what method, or whether the lot on sale is the lot that was tested.