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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 and the shelf life of the powder.

39 questions · sorted by votes · page 1 of 2

36 votes 5 answers48k views
How do I read a Karl Fischer water content result on a lyophilised vial?

The method section is present, which is unusual enough that I want to make use of it. I would like to know the limits of what can be inferred from this. What I am…

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…

39 questions
lyophilisation
lyophilisation

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

17 questions
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…

438 questions
asked by fresh_bac 13k · 2.3 years ago
36 votes 5 answers31k views
How much of the gross mass of a 20 mg a GLP-1 receptor agonist vial is actually peptide?

Setup, so nobody has to ask: 20 mg · a GLP-1 receptor agonist. I have worked this out and I would like someone to find the error, because I suspect there is one. My…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by zainab_mustafa 16k · 2.0 years ago
32 votes5 answers32k views
How much of the gross mass of a 15 mg survodutide vial is actually peptide?

The particulars: 15 mg · survodutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not used an online calculator…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by marta_szymanska 17k · 19 months ago
32 votes 5 answers19k views
How much of the gross mass of a 2 mg orforglipron vial is actually peptide?

What I have: 2 mg · orforglipron. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is what…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by w_okoye 40k · 2.1 years ago
29 votes4 answers25k views
How much of the gross mass of a 10 mg liraglutide vial is actually peptide?

The case in front of me: 10 mg · liraglutide. I want the working, not the result — I need to be able to redo it with different numbers. I care about the precision as…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by bridget_nyathi 16k · 2.2 years ago
26 votes5 answers26k views
How much of the gross mass of a 2 mg retatrutide vial is actually peptide?

Details up front: 2 mg · retatrutide. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by net_peptide 16k · 2.2 years ago
25 votes5 answers54k views
How much of the gross mass of a 5 mg cagrilintide vial is actually peptide?

What I am working with: 5 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, for…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by stopper_core 50k · 2.2 years ago
25 votes 4 answers12k views
How much of the gross mass of a 10 mg oral semaglutide vial is actually peptide?

The case in front of me: 10 mg · oral semaglutide. Please show the division. I want to check my own against yours. I would like the general form as well as the…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by day_seven_trough 11k · 21 months ago
25 votes 5 answers7k views
How much of the gross mass of a 50 mg semaglutide vial is actually peptide?

The specifics, since they change the answer: 50 mg · semaglutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by jo_vandeberg 19k · 7 months ago
24 votes0 answers13k views
How much of the gross mass of a 40 mg liraglutide vial is actually peptide?

Concretely: 40 mg · liraglutide. I want the working, not the result — I need to be able to redo it with different numbers. I care about the precision as well as the…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by coring_risk 17k · 7 months ago
24 votes3 answers8.8k views
On a COA, what is the difference between "peptide content", "net peptide" and "gross weight"?

I have a COA in front of me with all of the following on it, and I cannot work out which of these numbers is the one I care about: Appearance: white lyophilised…

coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
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…

438 questions
purity
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…

788 questions
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…

39 questions
acetate-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…

87 questions
asked by Dr_Elias_Weiss 46k · 13 months ago
22 votes3 answers19k views
How much of the gross mass of a 5 mg a GLP-1 receptor agonist vial is actually peptide?

Stated plainly: 5 mg · a GLP-1 receptor agonist. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by Dr_Yusuf_Adeyemi 95k · 10 months ago
22 votes 5 answers13k views
What does a collapsed lyophilisation cake tell me about the vial?

I keep a written log of every draw with date, volume and syringe type. I want to understand what this actually establishes, as opposed to what it is being used to…

lyophilisation
lyophilisation

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

17 questions
vial-inspection
vial-inspection

What you can learn by looking: cake morphology, meniscus films, fibres versus stopper fragments versus true particulates, clarity after…

66 questions
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…

39 questions
asked by anja_hellstrom 13k · 10 months ago
22 votes5 answers13k views
How much of the gross mass of a 10 mg tirzepatide vial is actually peptide?

The case in front of me: 10 mg · tirzepatide. Please show the division. I want to check my own against yours. I would like the general form as well as the specific…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by b_delacroix 48k · 4 months ago
22 votes 5 answers11k views
How much of the gross mass of a 4 mg semaglutide vial is actually peptide?

The specifics, since they change the answer: 4 mg · semaglutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not used…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by pip_okonjo 11k · 2 months ago
22 votes 5 answers8k views
How much of the gross mass of a 4 mg survodutide vial is actually peptide?

For reference: 4 mg · survodutide. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor of…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by pip_okonjo 11k · 37 days ago
22 votes 2 answers7.6k views
How much of the gross mass of a 40 mg oral semaglutide vial is actually peptide?

The case in front of me: 40 mg · oral semaglutide. I want the working, not the result — I need to be able to redo it with different numbers. I care about the…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
residual-solvent
residual-solvent

Solvents left behind by synthesis and purification - acetonitrile, TFA, DMF, DCM - their ICH limits, how they are measured by headspace GC, and…

14 questions
asked by cold_lane 14k · 13 months ago
22 votes4 answers7.3k views
How much of the gross mass of a 60 mg mazdutide vial is actually peptide?

What I am working with: 60 mg · mazdutide. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so far, for…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by fresh_bac 13k · 38 days ago
21 votes2 answers36k views
How much of the gross mass of a 8 mg orforglipron vial is actually peptide?

Numbers first: 8 mg · orforglipron. I can do the algebra. I am not confident about the conversion factors. If there is a standard way to lay this out, I would rather…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by ines_delacruz 16k · 2.1 years ago
21 votes5 answers8.4k views
How much of the gross mass of a 40 mg tirzepatide vial is actually peptide?

The case in front of me: 40 mg · tirzepatide. I want the working, not the result — I need to be able to redo it with different numbers. I care about the precision as…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by fibre_or_fragment 12k · 2 months ago
21 votes5 answers5.1k views
Does a desiccant sachet in the box do anything useful?

This is a recurring problem with one particular shipping lane rather than a one-off. I want to know whether this is a real physical effect or an artefact of how it is…

storage
storage

Storage conditions and their evidence base: minus twenty degrees for powder, refrigerated for solution, protection from light, and what the…

646 questions
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…

39 questions
lyophilisation
lyophilisation

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

17 questions
asked by leah_ferrers 15k · 5 months ago
21 votes 4 answers4.2k views
How much does ambient humidity matter when opening a lyophilised vial?

I have both a purity figure and a content figure, which is why the discrepancy is visible. I suspect the usual explanation for this is wrong, or at least incomplete.…

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…

39 questions
lyophilisation
lyophilisation

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

17 questions
reconstitution
reconstitution

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

330 questions
asked by pierce_count 15k · 2 months ago
20 votes 5 answers22k views
How much of the gross mass of a 20 mg mazdutide vial is actually peptide?

Stated plainly: 20 mg · mazdutide. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude and it seems…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by olu_babatunde 14k · 20 months ago
20 votes 5 answers11k views
How much of the gross mass of a 60 mg cagrilintide vial is actually peptide?

Setup, so nobody has to ask: 60 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…

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…

438 questions
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…

39 questions
acetate-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…

87 questions
asked by seamus_brady 17k · 7 months ago
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