Adsorption, and the dose that stayed on the glass
At low concentrations a measurable fraction of peptide can adsorb to glass and plastic surfaces, and the loss is largest exactly where it is least expected.
Stability
Page 4 of 20 of this archive, newest first.
A supplier suspends shipping to Singapore after 17 consecutive customs detentions
The route did not close because of a rule about peptides.
Same mass, different molecule: why identity by mass is not identity
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.
A supplier suspends shipping to Ireland after 5 consecutive customs detentions
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.
A supplier suspends shipping to Nigeria after 19 consecutive customs detentions
The route did not close because of a rule about peptides.
Date of analysis, date of manufacture, and the gap between them
A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer than the paperwork admits.
What twenty companies say about storage, and what they have measured
What would make a difference is not a regulator. It is three lines on a certificate, all of which are already known to whoever wrote it.
A supplier suspends shipping to Canada after 9 consecutive customs detentions
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 intramuscular injection nobody intended
Longer needles reach muscle in lean limbs, and intramuscular delivery of a long-acting depot changes absorption in ways nobody wants.
A supplier suspends shipping to Germany after 20 consecutive customs detentions
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 batch number is the only thing connecting the page to the vial
The interval between manufacture and analysis is the most under-read figure on the page, and the one most likely to matter by the time a vial is opened.
Oxidation, and the peroxide that came in with the surfactant
Deamidation, oxidation, aggregation and hydrolysis account for nearly all of what happens to a peptide over time. Each has a characteristic residue, a characteristic…
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.
Asparagine, glycine, and the two residues that decide a shelf life
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.
Storage after reconstitution, and the evidence behind the numbers
The air shot before a pen injection removes air from the cartridge and confirms flow. Skipping it can mean a materially reduced dose, and it is skipped constantly.
The reviewer, the approver, and why regulated documents carry two names
Somebody has to be answerable for a release document. On most certificates in this market, nobody is named at all.