Four millimetres is enough, and the data says so
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.
Reconstitution
Page 9 of 12 of this archive, newest first.
What the nitrogen said
Peptide content is the number that tells you how much drug is in the vial. Almost nobody sells it, almost nobody buys it, and when we paid for it on nine vials the results…
Longer is not safer
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 question no chromatogram has ever answered
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
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.
Twenty-eight days is a number from somebody else’s product
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…
Four ways a peptide comes apart
Reversed-phase chromatography runs in an organic, acidic mobile phase that dissociates most non-covalent aggregates on the way to the detector.
One vial, four weeks, and the data that does not exist
An in-use period is established by a dedicated study on a specific formulation in a specific container at a specific concentration. Borrowing one from a marketed product is…
The empty half of every certificate of analysis
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.
Four ways a peptide comes apart
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.
Oxidation, and the peroxide that came in with the surfactant
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.
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.
What a 1 mL syringe does that a 0.3 mL syringe does not
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…
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…
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.
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.
Glass, elastomer, aluminium: a three-material argument about one closure
Particulate matter is the oldest quality attribute in injectable manufacture and the one a private buyer is best placed to assess without instrumentation.
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.
What we asked twenty suppliers about stability data
A retest date says that material should be re-examined before use. An expiry date says it should not be used. The trade uses the second word for the first concept.
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.