[Question] how do you actually verify dead space
Slightly embarrassed to be asking this, but: how do you actually verify dead space.
Asked WWB what volume they reconstitute to for their own stability testing and they answered in one line. Useful thing to know.
Why "more water" keeps confusing people, including me for a month.
The vial contains a fixed amount of peptide. Water changes nothing about that amount. What it changes is concentration, and concentration is the divisor between the dose you want and the volume you draw.
So doubling the water halves the concentration and doubles the units for the same dose. Nothing is diluted in any sense that matters; you are simply reading a bigger number off the same barrel. Pick the water volume that puts your usual dose on a whole number of units and life gets easier.
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.
Sceptical readings welcome. The confident ones are the ones I distrust.
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.
Are you accounting for the powder volume, or is that where the confusion is?
Correction: that gives 5 units, not what you have written. 30mg into 2mL is 15mg/mL and the division follows from there.
Correction: that gives 5 units, not what you have written.
Adding one thing — put the date on the label too. Concentration plus date and you can never mix two vials up.
aim the stream at the glass wall, not at the cake
the number you write down is the number you will trust at 6am
- 1If your calculation produces a fraction of a unit, the concentration is…7 comments in this branch · started by u/piotr_bruun