genuine question about mg/mL that I am slightly embarrassed to ask
Asking properly rather than in a comment on somebody else’s thread: genuine question about mg/mL that I am slightly embarrassed to ask. 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.…
Shook the first vial because nobody told me not to. It was fine, but I have swirled every one since.
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.
Shook the first vial because nobody told me not to.
Disagreeing with this line only: adding more water is not a safety margin, it is a different divisor.
bacteriostatic water has the preservative, sterile water does not
units are a volume on a U-100 syringe, not a dose
[removed by moderator]
I would not round that figure. At 1.67mg/mL a rounding error of two units is a real fraction of the intended amount.
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.
The lyophilised cake displaces a small volume, so the true concentration is very slightly lower than the arithmetic suggests.
This is the sentence that makes the rest unnecessary. Write it on the vial and the problem is gone.
Pushback on the syringe advice: a U-100 barrel reads units of volume. Calling them "doses" is how the confusion starts.