The degradation product that elutes underneath the parent peak
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.
Reconstitution
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Nine parcels, nine loggers, and one uncomfortable set of traces
The compendial definitions of cold, controlled cold and controlled room temperature permit specified excursions, and knowing the permitted band is the difference between an…
Sterility is not a percentage, which is the whole difficulty
Purity, content, identity, sterility and endotoxin are five separate determinations. A single sheet of paper carrying one of them is not evidence about the other four.
Why SSA can be entirely straightforward and still tell you nothing about bioburden
The Journal has read several hundred certificates from twenty companies. We set out what the documents actually cover, and what a reader is filling in from imagination.
Low endotoxin recovery: the interference nobody looks for
We submitted vials for endotoxin determination and report the results, the method and the laboratory, because a pyrogen figure without a method is as empty as a purity…
The convention nobody explains before handing over the vial
A unit is a volume. A dose is a mass. The bridge between them is concentration, and concentration is a number somebody has to calculate.
An error taxonomy for a market without a pharmacist
The recurring errors in this market are not exotic. They are a small set of arithmetic and reading failures, each capable of moving a dose by a factor of two or ten.
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.
Janoshik, Medutest, PeptideMeter, VendorInvestigate: a capability audit
Four independent services underpin confidence in this market. All four are competent at chemistry. Microbiology is a different accreditation, a different facility and a…
Reading a barrel: the graduation that is not the one you think
Dead space in the needle hub is a real and calculable loss, and it matters more at small volumes than anybody expects.
Why TFC can be entirely straightforward and still tell you nothing about bioburden
The Journal has read several hundred certificates from twenty companies. We set out what the documents actually cover, and what a reader is filling in from imagination.
What the four services actually offer, test by test
A compendial sterility test takes fourteen days of incubation and consumes the containers tested. That timescale is incompatible with the business model that made…
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.
What we asked twenty suppliers about stability data
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.
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…
Mean kinetic temperature is not the average temperature
A single-use logger records the air adjacent to itself at a fixed interval. Where it sits in the package, and how often it samples, determine what it can possibly detect.
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.
LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure
We submitted vials for endotoxin determination and report the results, the method and the laboratory, because a pyrogen figure without a method is as empty as a purity…
The pyrogen question has a price, and it is not the price of a purity run
A compendial sterility test takes fourteen days of incubation and consumes the containers tested. That timescale is incompatible with the business model that made…
What happens in solution that does not happen in the cake
Every degradation pathway accelerates by orders of magnitude on reconstitution, because the solvent that lyophilisation removed is the reagent most of them need.