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peptide-stability

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

832 questions · sorted by votes · page 35 of 35

2 votes5 answers3.9k views
Does oxidation dominate for oral semaglutide held at 30 °C?

Concretely: oxidation · 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,…

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 linnea_wahlberg 14k · 13 months ago
2 votes 3 answers3.5k views
How many freeze-thaw cycles will retatrutide at 5 mg/mL tolerate?

What I am working with: retatrutide · 5 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…

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 nynke_dekker 18k · 17 months ago
2 votes0 answers2.4k views
How long does ecnoglutide stay within specification at room temperature once reconstituted?

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

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 marta_szymanska 17k · 14 months ago
2 votes0 answers1.6k views
Is a GLP-1 receptor agonist at 4 mg/mL stable enough for eight weeks of multi-withdrawal use?

Numbers first: a GLP-1 receptor agonist · 4 mg/mL · eight weeks. I would rather be corrected now than propagate something wrong. I am specifically not interested in a…

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 Dr_Ravi_Selvarajah 42k · 6 months ago
2 votes2 answers798 views
How do I design a cheap two-point stability check at home?

I have continuous temperature data for the period in question, which is unusual and I would like to use it. I have read the obvious sources and they disagree with…

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
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 carys_meredith 17k · 17 days ago
2 votes0 answers791 views
Does tirzepatide adsorb measurably to the vial wall at 1 mg/mL?

The specifics, since they change the answer: tirzepatide · 1 mg/mL. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not…

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 gunnar_isaksen 16k · 7 months ago
2 votes0 answers686 views
How long does a GLP-1 receptor agonist stay within specification at 37 °C once reconstituted?

What I have: a GLP-1 receptor agonist · 37 °C. I would like to understand the steps well enough to explain them to someone else. I have access to a refrigerator with…

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 threadlock7 14k · 5 months ago
2 votes0 answers581 views
Would you re-test a GLP-1 receptor agonist after six weeks at room temperature, or accept the original certificate?

Details up front: a GLP-1 receptor agonist · six weeks · room temperature. This is a planning question. I know what my options are; I do not know how to weigh them.…

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 eighty_six_hours 16k · 6 months ago
1 vote 5 answers9.6k views
Does reconstituting dulaglutide with phosphate-buffered diluent change anything I should know about?

What I am working with: dulaglutide · phosphate-buffered diluent. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody…

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 retest_please 13k · 9 months ago
1 vote5 answers6.4k views
My survodutide vial sat at 2–8 °C for twenty-one days — is testing worth it before use?

The case in front of me: survodutide · 2–8 °C · twenty-one days. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in…

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 triple_agonist_q 37k · 5 months ago
1 vote 5 answers5k views
Does aggregation of a GLP-1 receptor agonist at 30 °C show up as a loss of content or of purity?

Setup, so nobody has to ask: aggregation · a GLP-1 receptor agonist · 30 °C. The empirical answer seems settled. The explanation does not. If the honest answer is…

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 cap_the_luer 15k · 6 months ago
1 vote 5 answers4.7k views
Is room temperature an acceptable storage condition for lyophilised tirzepatide?

Concretely: room temperature · tirzepatide. I want to know whether there is evidence behind this or only repetition. I have checked the obvious registries and…

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 threadlock7 14k · 3 months ago
1 vote 4 answers3.6k views
Is orforglipron at 20 mg/mL stable enough for sixteen weeks of multi-withdrawal use?

Stated plainly: orforglipron · 20 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 dmitri_savchuk 17k · 2 months ago
1 vote 4 answers3.5k views
What happens to survodutide after four weeks at 2–8 °C in solution?

Conditions: survodutide · four weeks · 2–8 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the question…

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 bea_forsberg 14k · 3 months ago
1 vote 2 answers1.8k views
How many freeze-thaw cycles will semaglutide at 20 mg/mL tolerate?

The case in front of me: semaglutide · 20 mg/mL. 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…

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 noor_alhassan 15k · 28 days ago
1 vote0 answers1.1k views
What happens to dulaglutide after two weeks at 2–8 °C in solution?

Stated plainly: dulaglutide · two weeks · 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
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 imani_dube 19k · 9 months ago