does mg/mL actually matter or is it forum lore at this point
does mg/mL actually matter or is it forum lore at this point. If this has been answered properly somewhere, link me and I will delete.
The failure modes I have actually seen posted here, in order of frequency.
One: reconstituting at a different volume than intended and not writing it down, so the next draw is based on a remembered concentration. Two: treating units as a dose rather than a volume, which breaks the moment the concentration changes. Three: assuming a syringe is U-100 when it is not.
All three are solved by the same two habits — do the arithmetic before the water goes in, and write the result on the glass. Neither costs anything and between them they cover almost every question this board gets.
Asked SGN what volume they reconstitute to for their own stability testing and they answered in one line. Useful thing to know.
Started reconstituting everything to a round concentration and the six-in-the-morning error rate went to zero.
Corrections welcome, especially the pedantic ones. Pedantry is how this board earns its reputation.
best — the order this archive was captured in
The arithmetic in full: concentration is mass over volume, so 15mg into 2mL gives 7.5mg/mL. A U-100 syringe is graduated at 100 units per millilitre, so 0.75mg is 0.75 divided by 7.5 millilitres, which is 10 units.
Agreed on the swirl. There is no reason to shake it and a good reason not to.
Is that a U-100 syringe? The barrel markings change the answer completely.
Small fix — a U-100 syringe is 100 units per mL. If yours is marked differently it is not U-100 and the whole calculation changes.
Disagree with the "more water is safer" framing. It is not safer, it is just a different number to divide by.
Working has to be shown on arithmetic posts. Added a note asking for it rather than removing this one.
Working has to be shown on arithmetic posts.
Adding one thing — put the date on the label too. Concentration plus date and you can never mix two vials up.
Pushback on the syringe advice: a U-100 barrel reads units of volume. Calling them "doses" is how the confusion starts.
the powder cake sits at the bottom, the volume you add is the volume that counts
How many mg in the vial and how many mL are you adding?
- 1Disagree with the "more water is safer" framing. It is not safer, it is just…6 comments in this branch · started by u/aleksi_lehtinen