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Newest first. 5.2k questions across 107 tags.

5.2k questions · page 215 of 217

34 votes 3 answers25k views
What is the thermal exposure on a Shanghai to Japan lane in summer?

The case in front of me: Shanghai · Japan. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if 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…

578 questions
international-shipping
international-shipping

Cross-border movement of research material: transit lanes and their thermal profiles, tracked versus untracked, declaration accuracy, and what…

471 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
asked by esther_vandeVelde 52k · 2.3 years ago
40 votes 5 answers65k views
How do I get 12 units out of a vial reconstituted to 5 mg/mL without guessing?

Conditions: 12 units · 5 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 mistake here that…

insulin-syringe
insulin-syringe

U-100 and U-40 insulin syringes as measuring instruments. A U-100 syringe is graduated in insulin units where 100 units equals 1 mL, so one unit…

244 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

764 questions
diluent-volume
diluent-volume

Choosing how much diluent to add, which is really a question about what you want your measurement resolution to be. Larger volumes buy you…

295 questions
asked by rhian_prydderch 23k · 2.3 years ago
2 votes 5 answers9.6k views
Why do two papers on SURMOUNT-1 report different headline figures?

This is a question about interpretation, not about whether to act — I will take action questions elsewhere. This is one of those things that everyone repeats and…

clinical-trials
clinical-trials

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

745 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

764 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 assay_blank 45k · 2.3 years ago
35 votes 5 answers77k views
Would you accept 97.9% on ecnoglutide from JEEP without a content assay?

For reference: 97.9% · ecnoglutide · JEEP. I am at the decision point and I would rather think it through than improvise. I would rather spend money on measurement…

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
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
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 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 seven_day_half 31k · 2.3 years ago
19 votes0 answers11k views
What does a method section on a QST report change about how I read it?

Conditions: method section · QST. I have the document in front of me and I can read the numbers. What I cannot do is interpret them. I am reasonably comfortable with…

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
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
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by cap_the_luer 14k · 2.3 years ago
4 votes5 answers28k views
Does testosterone recover on weight loss alone in men?

I have three data points across nine months, which I hope is enough to see a trend. I would like to know whether this claim survives contact with evidence. If the…

hormones
hormones

Endocrine changes accompanying substantial weight loss: sex hormone binding globulin, testosterone, oestradiol, cortisol and the reproductive…

13 questions
bloodwork
bloodwork

Laboratory monitoring: which panels are worth ordering, sensible intervals, reference-range versus optimal-range arguments, and how to read a…

296 questions
clinical-trials
clinical-trials

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

745 questions
asked by tare_and_weigh 12k · 2.3 years ago
17 votes 5 answers30k views
Does deamidation of survodutide at 30 °C show up as a loss of content or of purity?

The specifics, since they change the answer: deamidation · survodutide · 30 °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
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 ten_mg_vial 31k · 2.3 years ago
21 votes0 answers16k views
How do I tell reflux from an energy deficit on 800 kcal a day?

For reference: reflux · 800 kcal. Something has gone wrong and I would like to know how badly before I decide what to do. Nothing else in the setup changed, which is…

fatigue
fatigue

Tiredness on treatment: how much is energy deficit, how much is dehydration or electrolyte drift, how much is genuinely drug-attributable, and…

78 questions
nutrition
nutrition

Eating on a suppressed appetite: hitting nutritional targets inside a small energy budget, micronutrient risk, meal structure, and what the trial…

100 questions
electrolytes
electrolytes

Sodium, potassium and magnesium during reduced intake and GI losses: what the symptoms of a shortfall look like, when a panel is worth drawing,…

72 questions
asked by nkem_obiora 39k · 2.3 years ago
12 votes 4 answers34k views
What happens to tirzepatide after three weeks at 30 °C in solution?

The specifics, since they change the answer: tirzepatide · three weeks · 30 °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
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
tirzepatide
tirzepatide

A dual GIP and GLP-1 receptor agonist. Questions here cover the SURPASS and SURMOUNT programmes, the practical differences from a pure GLP-1…

370 questions
asked by carys_meredith 12k · 2.3 years ago
36 votes 5 answers70k views
Does dimerisation dominate for a GLP-1 receptor agonist held at minus 20 °C?

Setup, so nobody has to ask: dimerisation · a GLP-1 receptor agonist · minus 20 °C. The empirical answer seems settled. The explanation does not. If the honest answer…

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 oona_kekkonen 13k · 2.4 years ago
18 votes 5 answers48k views
Can I reconstitute dulaglutide at 3.33 mg/mL and still measure a small dose accurately?

Stated plainly: dulaglutide · 3.33 mg/mL. I am trying to build something sustainable rather than something thorough that I will abandon. I have already decided the…

diluent-volume
diluent-volume

Choosing how much diluent to add, which is really a question about what you want your measurement resolution to be. Larger volumes buy you…

295 questions
insulin-syringe
insulin-syringe

U-100 and U-40 insulin syringes as measuring instruments. A U-100 syringe is graduated in insulin units where 100 units equals 1 mL, so one unit…

244 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

764 questions
dulaglutide
dulaglutide

A once-weekly GLP-1 receptor agonist built on an Fc fusion rather than fatty-acid acylation. Use this tag for questions about the fusion-protein…

200 questions
asked by Dr_Otto_Lindqvist 72k · 2.4 years ago
34 votes 5 answers67k views
How do I photograph a vial so someone can actually assess it?

I have photographs before and after reconstitution if the visual detail matters. Everything I have found on this is either a forum aside or a product page, neither of…

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
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,…

313 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
asked by ben_akintola 10k · 2.4 years ago
25 votes3 answers19k views
Is 97.6% a realistic purity ceiling for cagrilintide given its chain length?

Stated plainly: 97.6% · cagrilintide. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude and it…

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
hplc
hplc

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

503 questions
peptide-mapping
peptide-mapping

Enzymatic digestion followed by LC-MS/MS to confirm sequence rather than just mass. The method that catches a scrambled sequence or a D-amino-acid…

103 questions
amylin
amylin

Amylin and its analogues, most prominently cagrilintide, as a satiety mechanism orthogonal to incretin signalling. Includes the pharmacology of…

237 questions
asked by ayo_fadipe 9.4k · 2.4 years 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…

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
dulaglutide
dulaglutide

A once-weekly GLP-1 receptor agonist built on an Fc fusion rather than fatty-acid acylation. Use this tag for questions about the fusion-protein…

200 questions
asked by plunger_stop 13k · 2.4 years ago
19 votes 5 answers30k views
Is there any published stability data for cagrilintide at room temperature?

Details up front: cagrilintide · room temperature. 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
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
amylin
amylin

Amylin and its analogues, most prominently cagrilintide, as a satiety mechanism orthogonal to incretin signalling. Includes the pharmacology of…

237 questions
asked by swab_stopper 8.8k · 2.4 years ago
26 votes 5 answers46k views
Is PIONEER-1 a fair comparison of oral semaglutide against its comparator arm?

Details up front: PIONEER-1 · oral semaglutide. I am asking for verification rather than opinion, ideally with something I can read myself. It is possible the…

clinical-trials
clinical-trials

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

745 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
tirzepatide
tirzepatide

A dual GIP and GLP-1 receptor agonist. Questions here cover the SURPASS and SURMOUNT programmes, the practical differences from a pure GLP-1…

370 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 rania_haddad 13k · 2.4 years ago
39 votes 4 answers50k views
How many freeze-thaw cycles will a GLP-1 receptor agonist at 2.5 mg/mL tolerate?

Numbers first: a GLP-1 receptor agonist · 2.5 mg/mL. I can find plenty of assertions about this and almost no reasoning, which is usually a sign that nobody has…

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
asked by klara_novotna 19k · 2.4 years ago
28 votes 5 answers29k views
Does eGFR tell me anything about hepatic fat on orforglipron?

Stated plainly: eGFR · orforglipron. 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 confident…

liver-enzymes
liver-enzymes

ALT, AST, GGT and ALP: what they do and do not indicate about hepatic fat, why enzymes are a poor surrogate for histology, and where non-invasive…

91 questions
mash
mash

Metabolic dysfunction-associated steatohepatitis: histological endpoints, resolution without worsening fibrosis, fibrosis improvement by stage,…

56 questions
bloodwork
bloodwork

Laboratory monitoring: which panels are worth ordering, sensible intervals, reference-range versus optimal-range arguments, and how to read a…

296 questions
kidney-function
kidney-function

eGFR, creatinine, cystatin C and albuminuria: the acute haemodynamic dip that is not injury, the renal outcome data from the FLOW programme, and…

141 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 birk_nordahl 16k · 2.4 years ago
35 votes 5 answers37k views
Is 36 mg weekly a defensible maintenance dose for orforglipron?

Numbers first: 36 mg · orforglipron. This is a planning question. I know what my options are; I do not know how to weigh them. What I want is the minimum viable…

maintenance-dose
maintenance-dose

Staying put: the lowest dose that holds a result, the difference between the maximum studied dose and the maximum useful dose, and what the…

54 questions
clinical-trials
clinical-trials

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

745 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

764 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 t_oyelaran 79k · 2.4 years ago
19 votes5 answers23k views
What does SURMOUNT-4 report at the 10 mg dose level?

Details up front: SURMOUNT-4 · 10 mg. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at anyone else’s…

clinical-trials
clinical-trials

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

745 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

764 questions
titration
titration

Stepwise dose increases over weeks, why the label schedules exist at all, and what tolerability-driven deviation from a schedule looks like in…

456 questions
asked by per_haugen 13k · 2.4 years ago
37 votes0 answers55k views
Does JEEP issue lot-specific documentation, or a batch certificate?

I have the report as a PDF with the chromatogram on page two, so I can quote specifics. I can parse the result. I am less sure what it licenses me to conclude. 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…

910 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
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by nils_karlberg 9.4k · 2.4 years ago
26 votes 5 answers62k views
Does holding at 1.7 mg for sixteen weeks before escalating reduce vomiting?

Numbers first: 1.7 mg · sixteen weeks · vomiting. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to know…

titration
titration

Stepwise dose increases over weeks, why the label schedules exist at all, and what tolerability-driven deviation from a schedule looks like in…

456 questions
vomiting
vomiting

Emesis as a reported adverse event: trial incidence, its relationship to dose escalation rate, dehydration risk, and when it stops being a…

57 questions
dose-escalation
dose-escalation

The decision to move up a step: what evidence supports a four-week interval, what happens when you compress it, and how trial protocols handled…

103 questions
asked by cold_lane 10k · 2.4 years ago
37 votes0 answers49k views
Does holding at 15 mg for sixteen weeks before escalating reduce reflux?

What I have: 15 mg · sixteen weeks · reflux. 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…

titration
titration

Stepwise dose increases over weeks, why the label schedules exist at all, and what tolerability-driven deviation from a schedule looks like in…

456 questions
gi-side-effects
gi-side-effects

The gastrointestinal cluster as a whole - nausea, vomiting, diarrhoea, constipation, reflux, early satiety - with trial incidence rates, dropout…

162 questions
dose-escalation
dose-escalation

The decision to move up a step: what evidence supports a four-week interval, what happens when you compress it, and how trial protocols handled…

103 questions
asked by p_mkhize 58k · 2.4 years ago
15 votes 5 answers26k views
Is a 25G drawing needle the right choice for drawing oral semaglutide at 1 mg/mL?

The case in front of me: a 25G drawing needle · oral semaglutide · 1 mg/mL. I would like the axes of comparison first and the recommendation second. I have tried the…

needle-gauge
needle-gauge

Gauge and length selection, the trade-off between draw time and tissue trauma, coring risk with larger-bore needles, and why a fixed-needle…

91 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…

96 questions
dead-space
dead-space

The volume trapped in the syringe hub and needle after the plunger bottoms out. It is small in absolute terms and large as a fraction of a small…

117 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 orla_ferriter 89k · 2.4 years ago