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peptide-stability

Page 28 of 38 · 908 questions tagged peptide-stability.

908 questions · sorted by votes · page 28 of 38

12 votes 5 answers18k views
Would you re-test liraglutide after ten weeks at 4 °C, or accept the original certificate?

The specifics, since they change the answer: liraglutide · ten weeks · 4 °C. I would like to define my thresholds before I have a result, for obvious reasons. I want…

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…

910 questions
peptide-stability
peptide-stability

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

908 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…

771 questions
liraglutide
liraglutide

A once-daily GLP-1 receptor agonist and the compound that established the class. Still relevant for its shorter half-life, its paediatric and…

235 questions
asked by nkem_obiora 39k · 2.2 years ago
12 votes 5 answers17k views
Is 2–8 °C an acceptable storage condition for lyophilised a GLP-1 receptor agonist?

Stated plainly: 2–8 °C · a GLP-1 receptor agonist. This is asserted often enough that I assumed it was established, and then I went looking for the source. I have…

storage
storage

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

701 questions
peptide-stability
peptide-stability

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

908 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…

327 questions
asked by Dr_Colm_Fitzhenry 69k · 16 months ago
12 votes0 answers16k views
Does deamidation of survodutide at 4 °C show up as a loss of content or of purity?

The particulars: deamidation · survodutide · 4 °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,…

908 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…

476 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…

833 questions
survodutide
survodutide

A GLP-1 and glucagon receptor dual agonist with a substantial published MASH dataset. Use this tag for its hepatic endpoints, its dose ladder, and…

225 questions
asked by nils_karlberg 9.4k · 23 months ago
12 votes5 answers15k views
Why does freeze-concentration shift pH during freezing?

Transit was eleven days with two scanning gaps, so the thermal history is partly inferred. I would like the mechanism, because I want to be able to reason about the…

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…

57 questions
peptide-stability
peptide-stability

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

908 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 s_kalniete 57k · 2.4 years ago
12 votes 5 answers14k views
How would I detect aggregation in a mazdutide vial without sending it to PeptideMeter?

The case in front of me: aggregation · mazdutide · PeptideMeter. Everything I have found on this is either a forum aside or a product page, neither of which I trust.…

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,…

908 questions
harm-reduction
harm-reduction

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

472 questions
mazdutide
mazdutide

A GLP-1 and glucagon receptor dual agonist developed primarily in China, with a distinct dose range and a fast-moving publication record.…

237 questions
peptidemeter
peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how…

107 questions
asked by shear_at_the_front 17k · 11 months ago
12 votes 5 answers14k views
Why does aggregation accelerate at 25 °C rather than proceeding linearly?

Setup, so nobody has to ask: aggregation · 25 °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,…

908 questions
storage
storage

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

701 questions
hplc
hplc

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

503 questions
asked by dead_volume 56k · 15 months ago
12 votes5 answers11k views
How would I detect aggregation in a GLP-1 receptor agonist vial without sending it to PeptideMeter?

Stated plainly: aggregation · a GLP-1 receptor agonist · PeptideMeter. Everything I have found on this is either a forum aside or a product page, neither of which 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,…

908 questions
harm-reduction
harm-reduction

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

472 questions
peptidemeter
peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how…

107 questions
asked by linnea_wahlberg 17k · 6 months ago
12 votes5 answers11k views
How many freeze-thaw cycles will mazdutide at 6.67 mg/mL tolerate?

Numbers first: mazdutide · 6.67 mg/mL. I can find plenty of assertions about this and almost no reasoning, which is usually a sign that nobody has checked. Assume no…

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…

57 questions
peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 questions
mazdutide
mazdutide

A GLP-1 and glucagon receptor dual agonist developed primarily in China, with a distinct dose range and a fast-moving publication record.…

237 questions
asked by anja_hellstrom 13k · 4 months ago
12 votes 5 answers8.6k views
Is 25 °C an acceptable storage condition for lyophilised a GLP-1 receptor agonist?

Setup, so nobody has to ask: 25 °C · a GLP-1 receptor agonist. This is asserted often enough that I assumed it was established, and then I went looking for the…

storage
storage

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

701 questions
peptide-stability
peptide-stability

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

908 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…

327 questions
asked by h_villanueva 70k · 10 months ago
12 votes 5 answers7.7k views
Is mazdutide at 6.67 mg/mL stable enough for two weeks of multi-withdrawal use?

Numbers first: mazdutide · 6.67 mg/mL · two weeks. I am asking for verification rather than opinion, ideally with something I can read myself. It is possible the…

peptide-stability
peptide-stability

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

908 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;…

149 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…

327 questions
mazdutide
mazdutide

A GLP-1 and glucagon receptor dual agonist developed primarily in China, with a distinct dose range and a fast-moving publication record.…

237 questions
asked by rania_haddad 13k · 2 months ago
12 votes 5 answers7.4k views
Does aspartimide formation of oral semaglutide at 30 °C show up as a loss of content or of purity?

Concretely: aspartimide formation · oral semaglutide · 30 °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,…

908 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…

476 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…

833 questions
oral-glp1
oral-glp1

Oral routes for GLP-1 receptor agonism: peptide formulations rescued by absorption enhancers such as SNAC, and true small molecules that need no…

219 questions
asked by Dr_Sara_Kuusela 28k · 6 months ago
12 votes2 answers7.3k views
Is oral semaglutide at 1 mg/mL stable enough for four weeks of multi-withdrawal use?

The particulars: oral semaglutide · 1 mg/mL · four weeks. Somebody stated this to me confidently and I would like to check it before repeating it. I would accept a…

peptide-stability
peptide-stability

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

908 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;…

149 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…

327 questions
oral-glp1
oral-glp1

Oral routes for GLP-1 receptor agonism: peptide formulations rescued by absorption enhancers such as SNAC, and true small molecules that need no…

219 questions
asked by swirl_dont_shake 10k · 5 months ago
12 votes1 answer7.1k views
Does deamidation of ecnoglutide at minus 20 °C show up as a loss of content or of purity?

For reference: deamidation · ecnoglutide · 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,…

908 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…

476 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…

833 questions
ecnoglutide
ecnoglutide

A long-acting GLP-1 receptor agonist with a cAMP-biased signalling profile. A niche tag, mostly used for mechanism questions about biased agonism…

223 questions
asked by gradient_slope 46k · 8 months ago
12 votes 2 answers6k views
How long does ecnoglutide stay within specification at 25 °C once reconstituted?

The case in front of me: ecnoglutide · 25 °C. I have done this once and I suspect I got away with it rather than got it right. For context: I keep records of every…

peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 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…

327 questions
ecnoglutide
ecnoglutide

A long-acting GLP-1 receptor agonist with a cAMP-biased signalling profile. A niche tag, mostly used for mechanism questions about biased agonism…

223 questions
asked by syringe_ninety 12k · 11 months ago
12 votes 1 answer5.4k views
Does deamidation of semaglutide at 40 °C show up as a loss of content or of purity?

The specifics, since they change the answer: deamidation · semaglutide · 40 °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,…

908 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…

476 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…

833 questions
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…

470 questions
asked by Dr_Elias_Weiss 25k · 3 months ago
12 votes0 answers4.6k views
My oral semaglutide vial sat at minus 20 °C for fourteen days — is testing worth it before use?

For reference: oral semaglutide · minus 20 °C · 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…

578 questions
peptide-stability
peptide-stability

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

908 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…

910 questions
oral-glp1
oral-glp1

Oral routes for GLP-1 receptor agonism: peptide formulations rescued by absorption enhancers such as SNAC, and true small molecules that need no…

219 questions
asked by bounty_hunter_q 15k · 5 months ago
12 votes 4 answers4.2k views
Why does deamidation accelerate at 40 °C rather than proceeding linearly?

The specifics, since they change the answer: deamidation · 40 °C. I would like the mechanism, because I want to be able to reason about the cases nobody has written…

peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 questions
hplc
hplc

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

503 questions
asked by Dr_Nadia_Farsi 104k · 2 months ago
12 votes4 answers2.1k views
Does racemisation of retatrutide at 2–8 °C show up as a loss of content or of purity?

What I have: racemisation · retatrutide · 2–8 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to know…

peptide-stability
peptide-stability

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

908 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…

476 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…

833 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by ravi_pillai 12k · 2 months ago
12 votes3 answers1.6k views
Is retatrutide at 20 mg/mL stable enough for sixteen weeks of multi-withdrawal use?

Setup, so nobody has to ask: retatrutide · 20 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,…

908 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;…

149 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…

327 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by harriet_lonsdale 35k · 14 days ago
11 votes 5 answers32k views
What happens to semaglutide after twelve weeks at room temperature in solution?

What I am working with: semaglutide · twelve weeks · room temperature. This is one of those things that everyone repeats and nobody derives. This matters practically,…

peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 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…

327 questions
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…

470 questions
asked by sunniva_dahl 22k · 2.3 years ago
11 votes 3 answers24k views
How long does orforglipron stay within specification at 25 °C once reconstituted?

What I am working with: orforglipron · 25 °C. Everything I have found on this is either a forum aside or a product page, neither of which I trust. I am comfortable…

peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 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…

327 questions
orforglipron
orforglipron

A non-peptide, orally bioavailable small-molecule GLP-1 receptor agonist studied in the ATTAIN programme. It is not a peptide, which changes…

219 questions
asked by Dr_Marek_Zielinski 27k · 21 months ago
11 votes 4 answers22k views
Does hydrolysis of retatrutide at 30 °C show up as a loss of content or of purity?

Details up front: hydrolysis · retatrutide · 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,…

908 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…

476 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…

833 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by harriet_lonsdale 35k · 15 months ago
11 votes 4 answers20k views
How many freeze-thaw cycles will orforglipron at 8 mg/mL tolerate?

Stated plainly: orforglipron · 8 mg/mL. Everything I have found on this is either a forum aside or a product page, neither of which I trust. I am comfortable with the…

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…

57 questions
peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 questions
orforglipron
orforglipron

A non-peptide, orally bioavailable small-molecule GLP-1 receptor agonist studied in the ATTAIN programme. It is not a peptide, which changes…

219 questions
asked by nynke_dekker 9.4k · 2.0 years ago
11 votes 5 answers19k views
Is there any published stability data for retatrutide at minus 20 °C?

What I am working with: retatrutide · minus 20 °C. This has the shape of a fact but I cannot find its origin. What I found instead were three secondary sources all…

peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 questions
clinical-trials
clinical-trials

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

745 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by rania_haddad 13k · 20 months ago