Independent analysis puts a QST exenatide lot at 98.4%, against 95.6% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Callum Brathwaite
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Archive — page 5
134 piecesOne vial, four weeks, and the data that does not exist
Every degradation pathway accelerates by orders of magnitude on reconstitution, because the solvent that lyophilisation removed is the reagent most of them need.
VendorInvestigate result on a Chengdu cagrilintide lot lands 3.1 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
The retest date and the expiry date are not the same document
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.
Medutest result on a Xi'an tirzepatide lot lands 2.1 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The reproducible spectrum: the single most useful thing a report can carry
None of what a checkable identity statement requires is commercially sensitive, and all of it is known to whoever produced the document.
The conservative convention: report the lower of two numbers
Aggregates dissociate in the mobile phase and are recorded as monomer. Only a size-based separation reports them.
Sarcopenia is a diagnosis, not a synonym for losing lean mass
The gap between a defensible recommendation and a confident one is where most of the harm in this subject lives.
Independent analysis puts a ERP survodutide lot at 95.6%, against 92.3% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
How a release document is put together in a regulated plant
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
A part per million, in context
Every instrument specification quoted in an advertisement is a best case obtained on a calibration mixture, not on a submitted vial.
The badge economy, and what it is actually certifying
Every step between the laboratory report and the product page removes information, and the badge is the last step.
What Medutest can tell you about a vial by weighing its water
Water is a reactant in hydrolysis, a plasticiser that mobilises the amorphous matrix, and a carrier for everything else. All three matter.
What Medutest can tell you about a vial by weighing its water
Water is a reactant in hydrolysis, a plasticiser that mobilises the amorphous matrix, and a carrier for everything else. All three matter.
VendorInvestigate result on a Guangzhou liraglutide lot lands 3.6 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Freezing a reconstituted vial: the ice-water interface problem
We set out what is known, what is inferred and what is simply assumed about the fortnight after a vial is opened.
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…
Two ways to lift a peptide into a vacuum, and why the answer differs
The ionisation method determines the charge states you see, the adducts you must account for, and the modifications you might destroy in the process.
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.
Which results should be repeated before they are investigated
What the pivotal programmes measured and how often, which is a more defensible template than most published monitoring schedules.