why does nobody talk about reconstitution
why does nobody talk about reconstitution. Searched first, found three threads that contradict each other, hence the post.
Wrote the date on the vial as well as the concentration after losing track of which one was opened first.
Shook the first vial because nobody told me not to. It was fine, but I have swirled every one since.
The dead space question sent me down a rabbit hole for a week. It is a fraction of a unit and it is the same every draw.
I will update this if the picture changes rather than quietly leaving it up.
best — the order this archive was captured in
If your calculation produces a fraction of a unit, the concentration is wrong for your dose. Change the water volume until the numbers land on whole units.
Working has to be shown on arithmetic posts. Added a note asking for it rather than removing this one.
Are you accounting for the powder volume, or is that where the confusion is?
This. Showing the working is the fastest way for somebody else to spot the mistake.
Disagree with the "more water is safer" framing. It is not safer, it is just a different number to divide by.
What is written on the vial right now?
I would not round that figure. At 5mg/mL a rounding error of two units is a real fraction of the intended amount.
I keep a laminated card in the drawer with the arithmetic on it. Looks ridiculous. Has never once let me draw the wrong volume.
Is that a U-100 syringe? The barrel markings change the answer completely.
Pushback on the syringe advice: a U-100 barrel reads units of volume. Calling them "doses" is how the confusion starts.
The arithmetic in full: concentration is mass over volume, so 30mg into 3mL gives 10mg/mL. A U-100 syringe is graduated at 100 units per millilitre, so 5mg is 5 divided by 10 millilitres, which is 50 units.
Correction: that gives 100 units, not what you have written. 5mg into 2mL is 2.5mg/mL and the division follows from there.