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Single comment threadYou are looking at one branch of genuine question about concentration that I am slightly embarrassed to ask — 38 comments in the full submission. View in context.
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c/reconstitution·submitted 3 months ago by u/julia_erdogan

genuine question about concentration that I am slightly embarrassed to ask

PSAbranch of 9 comments

genuine question about concentration that I am slightly embarrassed to ask. If this has been answered properly somewhere, link me and I will delete. The failure modes I have actually seen posted here, in order of frequency. One: reconstituting at a different volume than intended and not writing it down, so the next…

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9 comments, started 3 months ago
u/lyophile_lou72 points·3 months ago

the powder cake sits at the bottom, the volume you add is the volume that counts

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u/honest_syringe_maybe28 points·3 months ago

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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u/sock_puppet_spotter9 points·3 months ago

dead space in the needle hub is real and it is small

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u/oskar_kaufmann3 points·3 months ago

Right — the volume you add is the only variable you control here, and the cake does not change it meaningfully.

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u/signe_grimaldi1 point·3 months ago·edited

Right — the volume you add is the only variable you control here, and the cake does not change it meaningfully.

Disagreeing with this line only: adding more water is not a safety margin, it is a different divisor.

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u/anya_antonsen2 points·3 months ago

Shook the first vial because nobody told me not to. It was fine, but I have swirled every one since.

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u/nadia_kjaer0 points·3 months ago

Did the maths give you a whole number of units, or a fraction?

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u/reflux_report1 point·3 months ago

Pushback on the syringe advice: a U-100 barrel reads units of volume. Calling them "doses" is how the confusion starts.

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About c/reconstitution

The arithmetic and the technique. Bacteriostatic versus sterile water, reconstitution volume as a concentration choice, converting mg/mL into insulin-syringe units, dead space, swirl-not-shake, stopper coring, and how long a reconstituted vial is actually good for. Math errors get corrected fast and politely.

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