D-amino acids are invisible to mass spectrometry, and that is the whole problem
Stereochemical inversion changes the molecule, changes its biology, and changes its mass by exactly nothing.
The Supply Chain Dispatch
Holograms, QR codes and other things that are not verification
Reported from the analysis, not from a warning notice.
The health authority in Switzerland has issued a warning on falsified exenatide injection pens found in the legitimate supply chain. The Journal has reviewed the notice and the accompanying photographs; the distinguishing features are a batch-number font difference and a needle-shield colour, neither of which a patient could reasonably be expected to detect.
Comparison of 16 certificates supplied by the reseller against the laboratory’s public archive matched 7 of them to reports commissioned by other parties, in some cases more than a year earlier. The reseller did not respond to two written requests for comment.
Comparison of 16 certificates supplied by the reseller against the laboratory’s public archive matched 7 of them to reports commissioned by other parties, in some cases more than a year earlier. The reseller did not respond to two written requests for comment.
The document is the weakest link in this trade. A certificate is a PDF; a laboratory letterhead is an image; a lot number is a string. Nothing in the ordinary transaction allows a buyer to confirm that a given report was issued for a given vial, and the four independent services differ in whether they offer any lookup at all.
Rowena Ashcombe, community pharmacist and diabetes educator, said the underfill finding was the more consequential one. "Nobody is being poisoned by a low content figure. Everybody using that vial is out by a fifth in every calculation they make."
Our series on identity confirmation covers the analytical detection of substitution in detail, including the mass differences that correspond to the commonest related compounds.
Related coverage
Independent analysis puts a HJ exenatide lot at 98.4%, against 97.3% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
A number without a suitability record is a number from an unknown instrument
System suitability is the set of checks demonstrating that the instrument and method were performing adequately when your sample was injected. It is recorded as a matter of…
Electrospray, MALDI, and the choice that shapes every spectrum after it
The two ionisation techniques in general use produce different charge distributions, different adducts and different failure modes. Certificates almost never say which was…
What changed at BCH in September, and what the company will not say about it
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
Oxidation, and the peroxide that came in with the surfactant
We describe each pathway in enough chemical detail to explain why it is invisible to the method the trade uses, because that is the part which has practical consequences.