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peptide-stability

Page 11 of 35 · 832 questions tagged peptide-stability.

832 questions · sorted by votes · page 11 of 35

25 votes5 answers29k views
Does fibrillation dominate for ecnoglutide held at 4 °C?

The specifics, since they change the answer: fibrillation · ecnoglutide · 4 °C. I understand the observation; what I do not understand is the mechanism behind it. I…

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 pieter_maas 22k · 12 months ago
25 votes 5 answers28k views
What temperature does a domestic freezer actually hold?

This is a recurring problem with one particular shipping lane rather than a one-off. I would like help reading this properly rather than being told what conclusion to…

storage
storage

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

646 questions
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
asked by ahmed_zerouali 19k · 14 months ago
25 votes0 answers27k views
Would you re-test retatrutide after two weeks at 25 °C, or accept the original certificate?

What I am working with: retatrutide · two weeks · 25 °C. I am trying to build something sustainable rather than something thorough that I will abandon. I have already…

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 retest_please 13k · 23 months ago
25 votes5 answers22k views
Is 37 °C an acceptable storage condition for lyophilised oral semaglutide?

Conditions: 37 °C · oral semaglutide. 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. Is there…

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 g_paskevicius 44k · 8 months ago
25 votes 5 answers21k views
My dulaglutide vial sat at room temperature for forty-two days — is testing worth it before use?

Stated plainly: dulaglutide · room temperature · forty-two days. I am trying to build something sustainable rather than something thorough that I will abandon. I have…

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 void_volume 13k · 21 months ago
25 votes0 answers21k views
What happens to cagrilintide after six weeks at room temperature in solution?

Numbers first: cagrilintide · six weeks · room temperature. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. 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
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 nadia_kowalczyk 14k · 18 months ago
25 votes5 answers17k views
Does dimerisation of cagrilintide at 4 °C show up as a loss of content or of purity?

Stated plainly: dimerisation · cagrilintide · 4 °C. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me suspicious. My…

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 tabular_nums 47k · 16 months ago
25 votes 5 answers17k views
How many freeze-thaw cycles will survodutide at 3.33 mg/mL tolerate?

The case in front of me: survodutide · 3.33 mg/mL. I am trying to do this correctly the first time rather than learn it by getting it wrong. I have already made one…

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 esben_lykke 15k · 17 months ago
25 votes 5 answers15k views
Does racemisation of orforglipron at 40 °C show up as a loss of content or of purity?

Details up front: racemisation · orforglipron · 40 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to…

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 mala_venkatesh 21k · 7 months ago
25 votes 5 answers15k views
Would you re-test survodutide after four weeks at 40 °C, or accept the original certificate?

Conditions: survodutide · four weeks · 40 °C. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like…

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 jonas_ekstrom 18k · 20 months ago
25 votes 4 answers14k views
Does racemisation of retatrutide at 4 °C show up as a loss of content or of purity?

Details up front: racemisation · retatrutide · 4 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to…

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 lipid_panel_q 44k · 8 months ago
25 votes 5 answers12k views
Is 4 °C an acceptable storage condition for lyophilised tirzepatide?

Conditions: 4 °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. Is there data…

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 gel_pack_warm 13k · 9 months ago
25 votes 3 answers11k views
Does aggregation of cagrilintide at 2–8 °C show up as a loss of content or of purity?

Stated plainly: aggregation · cagrilintide · 2–8 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, 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
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 swab_and_wait 15k · 5 months ago
25 votes 5 answers9.6k views
Would you re-test mazdutide after sixteen weeks at minus 20 °C, or accept the original certificate?

What I have: mazdutide · sixteen weeks · minus 20 °C. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone can tell me…

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 Dr_Aoife_Brennan 50k · 4 months ago
25 votes 5 answers9.4k views
Why does aggregation accelerate at 2–8 °C rather than proceeding linearly?

Setup, so nobody has to ask: aggregation · 2–8 °C. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me suspicious. My…

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 fib4_reader 35k · 10 months ago
25 votes 5 answers7.4k views
Is there any published stability data for ecnoglutide at 37 °C?

The case in front of me: ecnoglutide · 37 °C. I want to know whether there is evidence behind this or only repetition. I have checked the obvious registries and…

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 felix_araya 17k · 10 months ago
24 votes 5 answers56k views
My oral semaglutide vial sat at 40 °C for three days — is testing worth it before use?

The particulars: oral semaglutide · 40 °C · three days. I would like to define my thresholds before I have a result, for obvious reasons. I want a plan with explicit…

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 Dr_Signe_Baldursdottir 46k · 2.3 years ago
24 votes 5 answers40k views
My a GLP-1 receptor agonist vial sat at 4 °C for seven days — is testing worth it before use?

Numbers first: a GLP-1 receptor agonist · 4 °C · seven days. This is a planning question. I know what my options are; I do not know how to weigh them. What I want is…

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 cap_the_luer 15k · 20 months ago
24 votes5 answers32k views
My tirzepatide vial sat at 30 °C for fourteen days — is testing worth it before use?

The particulars: tirzepatide · 30 °C · fourteen days. I am at the decision point and I would rather think it through than improvise. I would rather spend money on…

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 deamidation_watch 43k · 2.0 years ago
24 votes5 answers31k views
My oral semaglutide vial sat at 30 °C for three days — is testing worth it before use?

The specifics, since they change the answer: oral semaglutide · 30 °C · three days. I would like to define my thresholds before I have a result, for obvious reasons.…

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 mg_per_ml 12k · 2.2 years ago
24 votes 5 answers29k views
Does dimerisation dominate for mazdutide held at 40 °C?

Setup, so nobody has to ask: dimerisation · mazdutide · 40 °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 rune_thoresen 14k · 15 months ago
24 votes 5 answers26k views
Do I need to worry about the order I add diluent and swirl?

My setup is a refrigerator with a logger and a small work area I wipe down, nothing more. I have done this once and I suspect I got away with it rather than got it…

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
peptide-stability
peptide-stability

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

832 questions
injection-technique
injection-technique

Technique questions: angle, pinch versus flat, aspiration, injection speed, air bubbles, and the handling steps that determine whether you deliver…

90 questions
asked by cal_hennessy 14k · 18 months ago
24 votes5 answers25k views
Does oxidation dominate for liraglutide held at 4 °C?

Concretely: oxidation · liraglutide · 4 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically,…

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 Dr_Wren_Halliday 40k · 12 months ago
24 votes 4 answers24k views
How many freeze-thaw cycles will mazdutide at 1 mg/mL tolerate?

Numbers first: mazdutide · 1 mg/mL. I would like to understand the steps well enough to explain them to someone else. I have access to a refrigerator with a logger…

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 ilaria_bertone 43k · 22 months ago