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c/reconstitution·submitted 1 year ago by u/vito_beaulieu

the dead space question that gets asked weekly, answered properly

PSAbranch of 6 comments

the dead space question that gets asked weekly, answered properly. It is the sort of thing everyone half-believes and nobody writes down. Wrote the date on the vial as well as the concentration after losing track of which one was opened first. Asked MKM what volume they reconstitute to for their own stability testing…

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6 comments, started 1 year ago
u/sigrid_kaufmann17 points·1 year ago

Not quite. Bacteriostatic and sterile water are not interchangeable for a multi-draw vial, and the difference is the preservative.

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u/tl_dr_tina14 points·1 year ago

twice as much water halves the concentration and doubles the units for the same dose

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u/priya_weiss3 points·1 year ago

Reconstituted at 3mL when I meant to use a different volume. Caught it because the units looked wrong on the barrel. Now I write 6.67mg/mL on the glass before I put the cap back.

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u/saskia_rahimi1 point·1 year ago

if the maths gives you a fraction of a unit, change the concentration

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u/honest_syringe_20251 point·1 year ago·edited

label the vial with the date as well as the concentration

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u/kavya_radich7 points·1 year ago

write the concentration on the vial in marker, that is the whole post

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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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