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peptide-stability

Page 18 of 35 · 832 questions tagged peptide-stability.

832 questions · sorted by votes · page 18 of 35

19 votes0 answers2.6k views
How long does survodutide stay within specification at minus 20 °C once reconstituted?

The case in front of me: survodutide · minus 20 °C. I am trying to do this correctly the first time rather than learn it by getting it wrong. I have already made one…

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_Elias_Weiss 46k · 5 months ago
18 votes 5 answers34k views
Does aggregation dominate for a GLP-1 receptor agonist held at 40 °C?

What I am working with: aggregation · a GLP-1 receptor agonist · 40 °C. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make…

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 t_oyelaran 41k · 21 months ago
18 votes 5 answers29k views
Why does my reconstituted semaglutide go cloudy after 3 weeks at 4 °C?

My background is chemistry rather than physiology, which may explain where I am stuck. This is not behaving the way I expected and I want to understand the…

semaglutide
semaglutide

A GLP-1 receptor agonist with a fatty-acid-acylated backbone and a roughly one-week half-life, marketed for type 2 diabetes and for weight…

360 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
peptide-stability
peptide-stability

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

832 questions
endotoxin
endotoxin

Bacterial endotoxin: LAL and kinetic chromogenic methods, how an endotoxin limit is derived from a dose, why endotoxin survives autoclaving, and…

14 questions
asked by Dr_Ingrid_Baumgartner 39k · 14 months ago
18 votes 5 answers28k views
Is orforglipron at 5 mg/mL stable enough for sixteen weeks of multi-withdrawal use?

Stated plainly: orforglipron · 5 mg/mL · sixteen weeks. This is asserted often enough that I assumed it was established, and then I went looking for the source. I…

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 kwn_analytical 89k · 23 months ago
18 votes 5 answers28k views
Does hydrolysis produce a resolvable peak on a C8 column, or does it co-elute?

Details up front: hydrolysis · a C8 column. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to know how…

hplc
hplc

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

466 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
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 fiadh_cronin 14k · 17 months ago
18 votes 5 answers28k views
Does aspartimide formation dominate for tirzepatide held at 2–8 °C?

Concretely: aspartimide formation · tirzepatide · 2–8 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted…

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 jonas_ekstrom 18k · 2.0 years ago
18 votes5 answers27k views
Does ecnoglutide adsorb measurably to the vial wall at 5 mg/mL?

Concretely: ecnoglutide · 5 mg/mL. 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…

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 valentina_rossi 16k · 19 months ago
18 votes 5 answers24k views
Does aggregation dominate for mazdutide held at minus 80 °C?

Stated plainly: aggregation · mazdutide · minus 80 °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 b_delacroix 48k · 2.2 years ago
18 votes 5 answers20k views
Is survodutide at 2 mg/mL stable enough for three weeks of multi-withdrawal use?

Conditions: survodutide · 2 mg/mL · three weeks. 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
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 olu_babatunde 14k · 2.2 years ago
18 votes 5 answers20k views
Does oxidation dominate for liraglutide held at minus 80 °C?

Concretely: oxidation · liraglutide · minus 80 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just…

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 bufferline42 49k · 2.2 years ago
18 votes5 answers17k views
Does oxidation dominate for liraglutide held at room temperature?

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

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 day_seven_trough 11k · 22 months ago
18 votes5 answers15k views
What happens to tirzepatide after three weeks at minus 20 °C in solution?

For reference: tirzepatide · three weeks · minus 20 °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
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 tandem_gradient 85k · 7 months ago
18 votes4 answers15k views
Does aggregation dominate for cagrilintide held at minus 80 °C?

Setup, so nobody has to ask: aggregation · cagrilintide · minus 80 °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
hplc
hplc

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

466 questions
asked by valentina_rossi 16k · 12 months ago
18 votes 4 answers14k views
Is minus twenty degrees actually better than four degrees for lyophilised powder?

This is a recurring problem with one particular shipping lane rather than a one-off. These are treated as interchangeable and I do not think they are. If both are…

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 dana_wexler 15k · 7 months ago
18 votes 4 answers13k views
How long does ecnoglutide stay within specification at 2–8 °C once reconstituted?

The case in front of me: ecnoglutide · 2–8 °C. I am trying to do this correctly the first time rather than learn it by getting it wrong. I have already made one…

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 swirl_dont_shake 19k · 6 months ago
18 votes 5 answers13k views
Is dulaglutide at 8 mg/mL stable enough for sixteen weeks of multi-withdrawal use?

What I am working with: dulaglutide · 8 mg/mL · sixteen weeks. This is asserted often enough that I assumed it was established, and then I went looking for the…

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 yuki_morishita 19k · 12 months ago
18 votes 5 answers11k views
My cagrilintide vial sat at 40 °C for seven days — is testing worth it before use?

Details up front: cagrilintide · 40 °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 the…

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 mass_shift_18 14k · 13 months ago
18 votes0 answers10k views
Would you re-test dulaglutide after two weeks at minus 80 °C, or accept the original certificate?

Stated plainly: dulaglutide · two weeks · minus 80 °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 plunger_stop 18k · 2.4 years ago
18 votes 5 answers10k views
My liraglutide vial sat at room temperature for fourteen days — is testing worth it before use?

The particulars: liraglutide · room temperature · fourteen days. I am at the decision point and I would rather think it through than improvise. I would rather spend…

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 nominal_ten 14k · 10 months ago
18 votes 5 answers10k views
Does aspartimide formation dominate for tirzepatide held at minus 80 °C?

Concretely: aspartimide formation · tirzepatide · 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 kelvin_lam 11k · 4 months ago
18 votes 5 answers9.3k views
How would I detect dimerisation in a GLP-1 receptor agonist vial without sending it to PeptideMeter?

What I am working with: dimerisation · a GLP-1 receptor agonist · PeptideMeter. This is a procedural question rather than a theoretical one, and I would like the…

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 h_villanueva 50k · 6 months ago
18 votes 2 answers9.1k views
What happens to cagrilintide after sixteen weeks at 30 °C in solution?

Numbers first: cagrilintide · sixteen weeks · 30 °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
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 sinead_gaffney 14k · 13 months ago
18 votes 5 answers8.9k views
How long does oral semaglutide stay within specification at 4 °C once reconstituted?

The particulars: oral semaglutide · 4 °C. I have read the obvious sources and they disagree with each other, so I would rather ask people who have actually done this.…

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 ekaterina_volk 16k · 2 months ago
18 votes 5 answers8.9k views
Is orforglipron at 8 mg/mL stable enough for sixteen weeks of multi-withdrawal use?

What I am working with: orforglipron · 8 mg/mL · sixteen weeks. This is asserted often enough that I assumed it was established, and then I went looking for the…

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 tobias_reint 19k · 7 months ago