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peptide-stability

Page 31 of 35 · 832 questions tagged peptide-stability.

832 questions · sorted by votes · page 31 of 35

6 votes 2 answers14k views
Does oral semaglutide adsorb measurably to the vial wall at 4 mg/mL?

For reference: oral semaglutide · 4 mg/mL. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not used an online calculator…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 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
storage
storage

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

646 questions
asked by jonas_ekstrom 18k · 23 months ago
6 votes 5 answers14k views
How many freeze-thaw cycles will oral semaglutide at 10 mg/mL tolerate?

The particulars: oral semaglutide · 10 mg/mL. I want a method I can write down and repeat, not a rule of thumb. I would rather over-engineer this than discover a…

freeze-thaw
freeze-thaw

What repeated freezing does to a peptide in solution: ice-crystal shear at the growing front, freeze-concentration of solutes, pH shifts as buffer…

55 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
asked by wren_calloway 14k · 15 months ago
6 votes 5 answers12k views
Why did my solution foam when I added the diluent, and does it matter?

I have a logging thermometer, a box of insulin syringes and no illusions about my worktop being sterile. I have a result I cannot explain, and I would rather diagnose…

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
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
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
asked by rukhsana_iqbal 14k · 18 months ago
6 votes5 answers12k views
Is 2–8 °C an acceptable storage condition for lyophilised ecnoglutide?

For reference: 2–8 °C · ecnoglutide. Somebody stated this to me confidently and I would like to check it before repeating it. I would accept a well-reasoned negative…

storage
storage

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

646 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by plunger_stop 18k · 19 months ago
6 votes 5 answers11k views
How long does tirzepatide stay within specification at 25 °C once reconstituted?

The particulars: tirzepatide · 25 °C. I want a method I can write down and repeat, not a rule of thumb. I would rather over-engineer this than discover a problem…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by Dr_Tomas_Kral 37k · 14 months ago
6 votes 5 answers11k views
Does aspartimide formation dominate for liraglutide held at minus 80 °C?

Concretely: aspartimide formation · liraglutide · minus 80 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
asked by nadia_kowalczyk 14k · 13 months ago
6 votes5 answers11k views
Does fibrillation of ecnoglutide at 37 °C show up as a loss of content or of purity?

The specifics, since they change the answer: fibrillation · ecnoglutide · 37 °C. I would like the mechanism, because I want to be able to reason about the cases…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 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
asked by v_ramaswamy 40k · 2.1 years ago
6 votes5 answers9.9k views
Would you re-test orforglipron after two weeks at 40 °C, or accept the original certificate?

Setup, so nobody has to ask: orforglipron · two weeks · 40 °C. I am trying to build something sustainable rather than something thorough that I will abandon. I have…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
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
asked by one_ml_bac 12k · 8 months ago
6 votes 5 answers8.8k views
Does hydrolysis of retatrutide at 37 °C show up as a loss of content or of purity?

Details up front: hydrolysis · retatrutide · 37 °C. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 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
asked by two_point_four 14k · 16 months ago
6 votes 5 answers8k views
Is there any published stability data for liraglutide at minus 80 °C?

For reference: liraglutide · minus 80 °C. I would like to know whether this claim survives contact with evidence. If the answer is "nobody has tested that", I would…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
asked by fibre_or_fragment 12k · 22 months ago
6 votes 5 answers7.4k views
Does deamidation dominate for ecnoglutide held at 4 °C?

The particulars: deamidation · ecnoglutide · 4 °C. I would like the mechanism, because I want to be able to reason about the cases nobody has written about. I have…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
asked by forty_units 14k · 20 months ago
6 votes3 answers6.1k views
Is liraglutide at 4 mg/mL stable enough for twelve weeks of multi-withdrawal use?

The particulars: liraglutide · 4 mg/mL · twelve weeks. I would like to know whether this claim survives contact with evidence. If the answer is "nobody has tested…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
bacteriostatic-water
bacteriostatic-water

Water for injection containing roughly 0.9 per cent benzyl alcohol as a bacteriostatic agent. It suppresses growth in a multiple-withdrawal vial;…

112 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by p_mkhize 41k · 7 months ago
6 votes 3 answers5.3k views
Is 2–8 °C an acceptable storage condition for lyophilised tirzepatide?

Concretely: 2–8 °C · tirzepatide. The claim is plausible, which is exactly why I want to check it. I am able to read a paper if someone points me at one. Has anyone…

storage
storage

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

646 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by t_oyelaran 41k · 9 months ago
6 votes5 answers5.3k views
Would you re-test survodutide after four weeks at minus 20 °C, or accept the original certificate?

The case in front of me: survodutide · four weeks · minus 20 °C. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
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
asked by rota_site 55k · 2 months ago
6 votes 5 answers3.2k views
How long does orforglipron stay within specification at minus 80 °C once reconstituted?

What I am working with: orforglipron · minus 80 °C. This is a procedural question rather than a theoretical one, and I would like the procedure rather than the…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by ravi_pillai 16k · 3 months ago
6 votes0 answers2.8k views
Does fibrillation dominate for ecnoglutide held at 37 °C?

For reference: fibrillation · ecnoglutide · 37 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two review…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
asked by orla_sheridan 14k · 18 months ago
6 votes 4 answers2.1k views
What happens to retatrutide after eight weeks at 25 °C in solution?

Setup, so nobody has to ask: retatrutide · eight weeks · 25 °C. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by lane_transit 42k · 22 days ago
6 votes1 answer1.6k views
Is there any published stability data for tirzepatide at 2–8 °C?

The specifics, since they change the answer: tirzepatide · 2–8 °C. I would like to know whether this claim survives contact with evidence. If the answer is "nobody…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
asked by bea_castellanos 47k · 6 months ago
6 votes0 answers1.3k views
Does reconstituting semaglutide with sterile water for injection change anything I should know about?

The case in front of me: semaglutide · sterile water for injection. This is one of those things that everyone repeats and nobody derives. This matters practically,…

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
bacteriostatic-water
bacteriostatic-water

Water for injection containing roughly 0.9 per cent benzyl alcohol as a bacteriostatic agent. It suppresses growth in a multiple-withdrawal vial;…

112 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
asked by eoin_mcgarry 16k · 2 months ago
5 votes5 answers19k views
How would I detect aspartimide formation in a liraglutide vial without sending it to Janoshik?

The case in front of me: aspartimide formation · liraglutide · Janoshik. I am trying to do this correctly the first time rather than learn it by getting it wrong. I…

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
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

445 questions
asked by anders_vestby 17k · 2.3 years ago
5 votes4 answers18k views
Does dimerisation dominate for cagrilintide held at minus 80 °C?

What I am working with: dimerisation · cagrilintide · minus 80 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

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

646 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
asked by dmitri_savchuk 17k · 2.3 years ago
5 votes 5 answers15k views
Is 25 °C an acceptable storage condition for lyophilised liraglutide?

The case in front of me: 25 °C · liraglutide. The claim is plausible, which is exactly why I want to check it. I am able to read a paper if someone points me at one.…

storage
storage

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

646 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by pip_okonjo 11k · 2.0 years ago
5 votes5 answers15k views
My survodutide vial sat at room temperature for twenty-one days — is testing worth it before use?

The case in front of me: survodutide · room temperature · twenty-one days. The failure mode I am trying to avoid is making this decision emotionally. I have twelve…

cold-chain
cold-chain

Keeping material within a temperature window from manufacture to use: phase-change packs versus dry ice, thermal mass, transit-lane temperature…

524 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
asked by k_szabo 45k · 21 months ago
5 votes 5 answers13k views
Does survodutide adsorb measurably to the vial wall at 3.33 mg/mL?

Concretely: survodutide · 3.33 mg/mL. Please show the division. I want to check my own against yours. I would like the general form as well as the specific number, so…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 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
storage
storage

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

646 questions
asked by fresh_bac 13k · 17 months ago