[Discussion] concentration is doing more work than we give it credit for
The title is the argument: concentration is doing more work than we give it credit for. Here is the rest of it.
Asked JEEP 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.
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.
That is everything I have. The rest is opinion and I have tried to keep it out.
best — the order this archive was captured in
The lyophilised cake displaces a small volume, so the true concentration is very slightly lower than the arithmetic suggests. It is a fraction of a percent and it is dwarfed by fill tolerance.
Left up and flaired Explainer — the numbers in this one check out.
if the maths gives you a fraction of a unit, change the concentration
Yes, and the dead-space point is worth repeating: it is small, it is real, and it is the same for every draw.
Spent 10 weeks confused about this until somebody drew the table for me. 5mg, 2mL, 2.5mg/mL, 0.25mg is 10 units. That is the whole thing.
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.