Reading a barrel in the wrong increments
We have catalogued what readers report, ranked by the size of the dosing error each produces.
Reconstitution
Page 10 of 12 of this archive, newest first.
Reading a barrel: the graduation that is not the one you think
We work through the arithmetic in full, because it is short, and because the errors it prevents are order-of-magnitude errors.
The four testing services and the study none of them can run
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.
Adsorption, and the dose that stayed on the glass
Bacteriostatic water contains benzyl alcohol at 0.9 per cent, which inhibits microbial growth in a preserved multiple-dose presentation. It does not sterilise a contaminated…
The four testing services and the study none of them can run
Storage instructions in this market are close to uniform and almost never accompanied by the study that would justify them. Uniformity is a sign of convention, not of…
What VendorInvestigate charges to answer the pyrogen question
Bacterial endotoxin is a heat-stable lipopolysaccharide from the outer membrane of Gram-negative organisms. It survives sterilisation, passes a sterilising filter, and is…
The question no chromatogram has ever answered
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.
One column, one wavelength, one very large blind spot
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.
A lyophilised peptide is not stable. It is slow.
We set out what the cycle does, in order, so that a reader can see which of its steps a rushed operation shortens first.
How a correct calculation becomes a wrong dose
We have catalogued what readers report, ranked by the size of the dosing error each produces.
Choosing a needle for a subcutaneous peptide
A 4 mm needle at ninety degrees without a skin pinch is adequate for essentially all adults. The persistence of 12.7 mm needles in this market is habit, not reasoning.
What we asked twenty suppliers about stability data
Storage instructions in this market are close to uniform and almost never accompanied by the study that would justify them. Uniformity is a sign of convention, not of…
What we are not saying about anybody in this trade
None of what this piece asks for is commercially sensitive, and all of it is already known to whoever released the batch.
Twenty-eight days is a number from somebody else’s product
Every degradation pathway accelerates by orders of magnitude on reconstitution, because the solvent that lyophilisation removed is the reagent most of them need.
Units, millilitres, milligrams: three scales on one small object
Insulin syringes are graduated in units on a convention that fixes 100 units to one millilitre. That convention says nothing about how much peptide is in a unit, and…
Gauge, pain and flow rate
Gauge affects pain and flow rate rather than depth. A finer needle is more comfortable and slower, and with a viscous solution the difference is noticeable.
The intramuscular injection nobody intended
A 4 mm needle at ninety degrees without a skin pinch is adequate for essentially all adults. The persistence of 12.7 mm needles in this market is habit, not reasoning.
What we asked twenty suppliers about stability data
We asked twenty companies three questions about stability data and print every answer, refusal and non-response.
Four ways a peptide comes apart
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.
What the sequence tells you about how a peptide will fail
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.