WWB names the synthesis and fill sites behind its catalogue
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
Testing Dispatch
PeptideMeter result on a Chengdu exenatide lot lands 3.6 points above the supplier’s stated figure
The supplier confirmed the determination and supplied the method behind its own figure inside a week.
A peptide content determination commissioned by the Journal on a 2 mg exenatide vial from GL Biochem has returned 98% of the labelled mass, the balance being the counter-ion and residual water that every lyophilised salt carries. Chromatographic purity on the same vial was above 96.1%. The two numbers measure different things, and this is one of the few certificates in the trade to print both.
Content by elemental nitrogen determination returned 98% of the labelled nominal mass, which on a 2 mg vial corresponds to roughly 5.50 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.
The Journal purchased 17 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.
Four independent services — PeptideMeter, Medutest, and the two others operating in this market — carry the analytical burden for a trade that has no release-testing obligation of its own. Each is paid by whoever submits the sample, which is usually the vendor. The Journal’s position is that a submitter-pays model is workable but that its incentive structure has to be stated whenever a result is quoted as verification.
Lorcan Feeney, analytical services director at an independent laboratory, 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."GL Biochem’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.
Related coverage
A vial can be 99.4 per cent pure and not sterile in the same afternoon
Every certificate circulating in this market answers a question about molecules. Almost none answers a question about organisms, pyrogens, or the integrity of the seal.
What twenty companies say about storage, and what they have measured
A stability programme needs a protocol, defined conditions, a stability-indicating method and time. Time is the ingredient no commercial testing service can sell.
Reading a certificate as a document rather than as a score
The purity figure is the least informative line on a well-constructed certificate and the only line most buyers read.
Janoshik result on a Hangzhou cagrilintide lot lands 0.9 points above the supplier’s stated figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
What the paperwork is for, and who it was designed to protect
The purity figure is the least informative line on a well-constructed certificate and the only line most buyers read.