anyone worked out a recon volume that puts 0.5mg on a round unit mark
#reconstitution 2026-05-05
Tuesday49 messages10 participantstimes are UTC
Highlights from this day
- rotterdam_recon — a slightly collapsed cake is cosmetic. a puddle in the bottom is not 17:52
- juno_joins — a 3ml syringe for the diluent and a u100 for the dose is the setup most people here end up with 18:53
- juno_joins — lyophilised powder is far more robust than people think. it is the solution that is fragile, from memory if you draw up with a bigger pin and inject with a fresh one… 18:54
- pinch_not_stretch — how much do i lose to dead space with a 31G pin 19:10
it should be completely clear with no floaters. cloudy means stop
does it matter if i inject the bac water straight at the powder
[edited]i use bac water even for a single-use vial because it stings less, which is not the reason it exists
a slightly collapsed cake is cosmetic. a puddle in the bottom is not
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aim the diluent at the glass wall, not at the powder. it goes in gentler
follow up 15mg in 3ml is 5mg/ml. same numbers as 10 in 2, just more of it
label the vial
swirl dont shake
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how do you all measure a half unit, or do you just not
yep 10 units
quick one 5mg in 2ml gives 2.5mg/ml, 0.25mg is 10 units. good for a starting dose, ask me again in a month
you can absolutely just always use 2ml, and honestly most of us should, i have it written down somewhere
20mg in 2ml is 10mg/ml. 1mg is 10 units, 2mg is 20 units, easy
swirl it. do not shake it. the foam is denatured protein and you are not getting it back
why does everyone say 2ml specifically and not 1ml
the vacuum will pull it in. let it. fighting it is how you get a face full of aerosol
do you draw up with the same pin you inject with
a 3ml syringe for the diluent and a u100 for the dose is the setup most people here end up with
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lyophilised powder is far more robust than people think. it is the solution that is fragile, from memory
if you draw up with a bigger pin and inject with a fresh one you lose a bit more to dead space
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right so is the meniscus reading actually a real source of error or am i overthinking
right so does benzyl alcohol matter if im finishing the vial in one go
does temperature of the bac water matter at all
right so how long after reconstituting before its actually dissolved
is a slightly cloudy solution ever ok or is that always a bin it
how much do i lose to dead space with a 31G pin
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the jewellery scale is a good habit but calibrate it, they drift badly
if you cannot read the mark confidently, your volume is too small. redo it at a lower concentration, ask me again in a month
weigh it first
i swirl for about thirty seconds and then leave it. never had one fail to dissolve
the powder is stuck to the stopper, do i care
the last few units are a real loss. i accept it rather than tilting the vial and drawing air
nope, redo it
ok so anyone else find the 20mg vials harder to get fully dissolved than the small ones
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read it at eye level
do not add more bac water to an already reconstituted vial, you have lost track of the concentration
19:50tenpence pinned a message
bac water
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update from 11 months ago: switched to a single concentration and have not miscalculated since
the meniscus thing is real. read it at eye level or you are guessing by a unit either way
if the powder is on the stopper, tap it down before you add anything. it will still dissolve either way
it foamed. is it ruined
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benzyl alcohol is what makes it bacteriostatic. it is about 0.9% typically
not sterile water
check your maths
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ok so my vial pulled the water in on its own, is that the vacuum or did i do something
if you draw up with a bigger pin and inject with a fresh one you lose a bit more to dead space
gross powder mass is not net peptide. water and counterion are in that number
is it worth buying a 3ml syringe for the diluent or is the insulin one fine
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