Dr.LipidDallas said:Reconstitution tip for anyone mixing dosing arithmetic from lyophilized powder: use bacteriostatic water, NOT sterile water.
Compounding pharmacy dose accuracy check for dosing arithmetic: I always verify my first dose from a new vial by weighing it on a milligram scale. Draw up your dose, weigh the syringe, subtract empty syringe weight, compare to expected water weight at that volume.
For a 10-unit dose (0.1mL): expected weight ~100mg of water. If it's significantly off, your syringe may be inaccurate. Cheap insulin syringes can have ±5% volume accuracy. Spring for quality brands like BD or Terumo.
carlos_SATX said:Agreed, and it is worth saying that rounding to the nearest whole unit is usually acceptable at maintenance doses and is not acceptable at the bottom…
Genuinely useful, thank you. I had the facts and not the framework. Printing the relevant bit and taking it with me.
Dr.LipidDallas said:Reconstitution tip for anyone mixing dosing arithmetic from lyophilized powder: use bacteriostatic water, NOT sterile water.
Comparison of compounded dosing arithmetic delivery formats I've tried:
| Format | Pros | Cons |
|---|---|---|
| Lyophilized vial | Longest shelf life, lowest cost | Requires reconstitution |
| Pre-mixed vial | Ready to draw up | Shorter shelf life (28-45 days) |
| Pre-filled syringes | Most convenient | Higher cost, shorter shelf life |
| Sublingual drops | No needles | Lower bioavailability, less data |
I use lyophilized vials for cost and stability. The reconstitution takes 30 seconds once you've done it a few times.
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Shop Reference StandardsDr.ObesityMed said:Two of us with identical vials and identical diluent arrived at different unit counts, which means one of us has a conceptual error rather than a…
Regarding dosing arithmetic multi-dose vial contamination prevention: after reconstituting, I wipe the vial stopper with a fresh alcohol swab before EVERY single draw. I also never touch the stopper with my fingers and use a new needle for each draw.
Even with bacteriostatic water preservative, contamination is cumulative. One sloppy draw can introduce bacteria that multiply over days. Aseptic technique isn't optional — it's essential for injectable medications.