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water-content

Page 3 of 3 · 51 questions tagged water-content.

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51 questions · sorted by votes · page 3 of 3

4 votes 2 answers2.4k views
How much does ambient humidity matter when opening a lyophilised vial?

The lot number on the vial matches the certificate, which at least rules out the easy problem. I want to know whether this is a real physical effect or an artefact of…

water-content
water-content

Residual moisture in a lyophilised solid, measured by Karl Fischer titration or loss on drying. It drives both the mass balance on a content assay…

51 questionslyophilisation
lyophilisation

Freeze-drying: primary and secondary drying, collapse temperature, the role of bulking agents and cryoprotectants such as mannitol and trehalose,…

17 questionsreconstitution
reconstitution

Taking a lyophilised vial to a solution of known concentration: choice of diluent, volume selection, how to add liquid without shearing the cake,…

313 questionsasked by mala_venkatesh 22k · 20 days ago
2 votes 5 answers5.4k views
How much of the gross mass of a 20 mg cagrilintide vial is actually peptide?

What I am working with: 20 mg · cagrilintide. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so far,…

content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

476 questionswater-content
water-content

Residual moisture in a lyophilised solid, measured by Karl Fischer titration or loss on drying. It drives both the mass balance on a content assay…

51 questionsacetate-content
acetate-content

Counter-ion content, most often acetate or trifluoroacetate, and why it matters: the counter-ion and residual water are part of the gross mass you…

88 questionsamylin
amylin

Amylin and its analogues, most prominently cagrilintide, as a satiety mechanism orthogonal to incretin signalling. Includes the pharmacology of…

237 questionsasked by Dr_Ravi_Selvarajah 35k · 13 months ago
1 vote0 answers1.4k views
Would a Karl Fischer water content test distinguish deamidation from a synthesis impurity in dulaglutide?

Conditions: a Karl Fischer water content test · deamidation · dulaglutide. I would like the axes of comparison first and the recommendation second. I have tried the…

peptide-mapping
peptide-mapping

Enzymatic digestion followed by LC-MS/MS to confirm sequence rather than just mass. The method that catches a scrambled sequence or a D-amino-acid…

103 questionspurity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questionsmass-spec
mass-spec

Mass spectrometry for identity confirmation: electrospray ionisation, multiple charge states, monoisotopic versus average mass, deconvolution, and…

52 questionswater-content
water-content

Residual moisture in a lyophilised solid, measured by Karl Fischer titration or loss on drying. It drives both the mass balance on a content assay…

51 questionsdulaglutide
dulaglutide

A once-weekly GLP-1 receptor agonist built on an Fc fusion rather than fatty-acid acylation. Use this tag for questions about the fusion-protein…

200 questionsasked by mira_sundqvist 7.1k · 10 months ago