does bacteriostatic water actually matter or is it forum lore at this point
Genuine question, and the title is the question: does bacteriostatic water actually matter or is it forum lore at this point.
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.
If two or three other people have done the same thing we might actually learn something. Alone it is an anecdote.
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.
What is written on the vial right now?
20mg into 2mL is 10mg/mL, and 5mg of that is 50 units
label the vial with the date as well as the concentration
more water is not more drug, it is the same drug in a bigger volume
bacteriostatic water has the preservative, sterile water does not
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That only works if the fill weight is exactly the label weight, and it usually is not exactly anything.
Is that a U-100 syringe? The barrel markings change the answer completely.
Aim the stream down the wall of the vial rather than into the cake. Reconstitution is a solubility problem, not a mixing problem, and mechanical shear does nothing helpful.
Left up and flaired Explainer — the numbers in this one check out.
Adding more water does not change how much peptide is in the vial. It changes the concentration, which changes the volume you draw for the same amount. That is the entire relationship.
twice as much water halves the concentration and doubles the units for the same dose
twice as much water halves the concentration and doubles the units for the same dose
nadia_kjaer has the units point exactly right. They are a volume on the barrel and nothing else.
Did the maths give you a whole number of units, or a fraction?
Not quite. Bacteriostatic and sterile water are not interchangeable for a multi-draw vial, and the difference is the preservative.
Disagree with the "more water is safer" framing. It is not safer, it is just a different number to divide by.
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