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.
Sterility
Page 6 of 7 of this archive, newest first.
Turnaround, cost and accreditation across the services this trade relies on
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 fourteen-day problem, and what it does to a commercial testing model
Endotoxin is the more tractable of the two questions, and a kinetic chromogenic determination is neither slow nor exotic. It is simply not on the menu.
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.
The intramuscular injection nobody intended
The insulin injection-technique literature is large, well conducted and directly transferable on questions of depth and tissue. We say where it stops transferring.
The convention nobody explains before handing over the vial
Dead space in the needle hub is a real and calculable loss, and it matters more at small volumes than anybody expects.
What Medutest charges to answer the pyrogen question
The masking phenomenon known as low endotoxin recovery means a formulation can return a clean result while containing endotoxin the assay cannot see.
Reading a barrel in the wrong increments
We have catalogued what readers report, ranked by the size of the dosing error each produces.
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.
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.
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.
Endotoxin is not a microorganism, and killing the bacteria does not remove it
Three compendial method families are in routine use and a fourth, based on a recombinant enzyme rather than crab lysate, is now compendial in its own right.
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…
The fourteen-day problem, and what it does to a commercial testing model
We asked all four services what they can determine, on what timescale, at what price, and under what accreditation. The answers are printed in full.
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.
The one place the insulin literature and this class agree completely
Repeated injection into the same small area produces lipohypertrophy — thickened, rubbery subcutaneous tissue with blunted and erratic absorption. It is common, it is…
Why a dead-clean sterile filter can pass pyrogen straight through
Bacterial endotoxin is a heat-stable lipopolysaccharide from the outer membrane of Gram-negative organisms. It survives sterilisation, passes a sterilising filter, and is…
How a correct calculation becomes a wrong dose
Almost every case involves a change — a new vial, a new syringe size, a new supplier — carried forward with an old number.
Why a dead-clean sterile filter can pass pyrogen straight through
Bacterial endotoxin is a heat-stable lipopolysaccharide from the outer membrane of Gram-negative organisms. It survives sterilisation, passes a sterilising filter, and is…