Independent analysis puts a TFC semaglutide lot at 99.0%, against 96.3% on the certificate
The result is unremarkable. What the report omits is not.
Roshan Devakumar
Page 8 of 12 of this archive, newest first.
Archive — page 8
227 piecesDeamidation is the commonest degradation route and the hardest to see
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.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
Resolving power and mass accuracy are two different specifications
Calibration drift is real, unremarkable, and the reason serious laboratories run internal standards.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
The degradation product that elutes underneath the parent peak
An isoaspartate rearrangement changes the molecule and not the mass. A method that confirms identity by molecular weight alone will report it as the parent compound.
Janoshik result on a Shenzhen liraglutide lot lands 1.2 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Asparagine, glycine, and the two residues that decide a shelf life
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.
PeptideMeter result on a Guangzhou liraglutide lot lands 3.3 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Asparagine, glycine, and the two residues that decide a shelf life
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
Six words a verification badge would need to mean anything
Every step between the laboratory report and the product page removes information, and the badge is the last step.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
What twenty companies say about storage, and what they have measured
A retest date says that material should be re-examined before use. An expiry date says it should not be used. The trade uses the second word for the first concept.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
Before anything is weighed, the peptide has to be charged
A brief and unromantic tour of the interface between a liquid sample and a vacuum.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.