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

help me understand dead space, I have read the wiki twice

Discussionbranch of 7 comments

Trying to get a straight answer on this: help me understand dead space, I have read the wiki twice. 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. The lyophilised cake displaces a small…

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7 comments, started 1 year ago
u/vito_beaulieu99 points·1 year ago

Started reconstituting everything to a round concentration and the six-in-the-morning error rate went to zero.

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u/bac_water_banditMOD65 points·1 year ago·edited

Reminder: this board does maths, not dosing. Nobody here tells another member what amount to take.

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u/priya_guerrero61 points·1 year ago

Spent 17 weeks confused about this until somebody drew the table for me. 5mg, 2mL, 2.5mg/mL, 0.75mg is 30 units. That is the whole thing.

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u/hub_opssite staff21 points·1 year ago

That is sterile water, not bacteriostatic. Same appearance, different product, and it matters for a multi-draw vial.

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u/freya_onwuka10 points·1 year ago

That is sterile water, not bacteriostatic.

Right, and the arithmetic behind it: 10mg in 2mL is 5mg/mL, so 1mg is 20 units.

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u/yusuf_achebe27 points·1 year ago

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.

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u/clara_weiss18 points·1 year ago

Adding more water does not change how much peptide is in the vial.

Adding one thing — put the date on the label too. Concentration plus date and you can never mix two vials up.

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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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