In-use periods, and the ones nobody can give you
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.
Reconstitution
Diluent choice, volume arithmetic, unit conversion, and the errors that recur.
Hydrolysis, isomerisation, and the arithmetic of a broken bond
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.
We asked four laboratories for a sterility test. Here is what came back.
Four independent services underpin confidence in this market. All four are competent at chemistry. Microbiology is a different accreditation, a different facility and a…
Four millimetres is enough, and the data says so
Longer needles reach muscle in lean limbs, and intramuscular delivery of a long-acting depot changes absorption in ways nobody wants.
In-use periods, and the ones nobody can give you
A needle blunts on first use. Reuse is uncomfortable, and it is a documented contributor to lipohypertrophy.
Why the independent testing market grew a chemistry arm and not a microbiology one
Four independent services underpin confidence in this market. All four are competent at chemistry. Microbiology is a different accreditation, a different facility and a…
Why a dead-clean sterile filter can pass pyrogen straight through
The masking phenomenon known as low endotoxin recovery means a formulation can return a clean result while containing endotoxin the assay cannot see.
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.
LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure
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.
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.
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.
Choosing a needle for a subcutaneous peptide
Skin thickness at the standard injection sites is approximately two millimetres in adults and varies remarkably little with body mass. That single finding is why short…
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…
One vial, four weeks, and the data that does not exist
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.
Janoshik, Medutest, PeptideMeter, VendorInvestigate: a capability audit
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.
Janoshik, Medutest, PeptideMeter, VendorInvestigate: a capability audit
The absence of microbiological capability in this market is a commercial fact with a straightforward explanation, and it is worth understanding before blaming anybody for it.
Reading a barrel: the graduation that is not the one you think
The graduation interval differs between barrel sizes, and a 1 mL barrel is frequently marked in two-unit steps. Reading one as though it were marked in single units halves…
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.
Twenty-eight days is a number from somebody else’s product
We set out what is known, what is inferred and what is simply assumed about the fortnight after a vial is opened.
A unit is not a dose, and it never was
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…