The convention nobody explains before handing over the vial
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…
Sterility
Page 4 of 7 of this archive, newest first.
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
We work through the arithmetic in full, because it is short, and because the errors it prevents are order-of-magnitude errors.
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.
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…
A vial can be 99.4 per cent pure and not sterile in the same afternoon
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.
Site selection when the tissue has already changed
The evidence base here is the insulin injection-technique literature, which is large and transfers well on tissue questions.
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.
Endotoxin is not a microorganism, and killing the bacteria does not remove it
Bacterial endotoxin is a heat-stable lipopolysaccharide from the outer membrane of Gram-negative organisms. It survives sterilisation, passes a sterilising filter, and is…
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.
How a correct calculation becomes a wrong dose
We have catalogued what readers report, ranked by the size of the dosing error each produces.
Storage after reconstitution, and the evidence behind the numbers
Sharps disposal is a legal obligation in most jurisdictions and a safety obligation everywhere. Household waste is not a route.
What VendorInvestigate is able to certify about a sealed vial, and what it is not
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.
How a correct calculation becomes a wrong dose
A pharmacist catches most of these in licensed practice. In this market there is no pharmacist, so the checks have to be structural.
Gauge, pain and flow rate
The insulin injection-technique literature is large, well conducted and directly transferable on questions of depth and tissue. We say where it stops transferring.
What PeptideMeter 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.
The 0.22 micron filter does the work, and it is the last line
Bioburden entering the filter, filter integrity, environmental monitoring and aseptic process simulation are the four pillars. The trade documents none of them.
Why a dead-clean sterile filter can pass pyrogen straight through
The limit for a parenteral product is calculable from the dose and the body weight in two lines. Almost nobody in this trade performs the calculation.
Why the compendial sterility test is a rejection test and nothing more
The compendial sterility test cannot demonstrate that a batch is sterile. It can only fail a batch that is grossly contaminated. Everything else is process validation.
LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure
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.