wendy_avl said:

Comparison of compounded dosing arithmetic delivery formats I've tried: Format Pros Cons Lyophilized vial Longest shelf life, lowest cost Requires…

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.

wendy_avl said:

Comparison of compounded dosing arithmetic delivery formats I've tried: Format Pros Cons Lyophilized vial Longest shelf life, lowest cost Requires…

Quick syringe math for dosing arithmetic dosing: if your vial is reconstituted at 5mg/2mL, that's 2.5mg/mL. For a 0.25mg dose you need 0.1mL = 10 units on an insulin syringe.

I keep a chart on my fridge:

• 0.25mg = 10 units
• 0.5mg = 20 units
• 1.0mg = 40 units
• 1.25mg = 50 units

Always double-check your concentration before drawing up!

wendy_avl said:

Comparison of compounded dosing arithmetic delivery formats I've tried: Format Pros Cons Lyophilized vial Longest shelf life, lowest cost Requires…

This answered a question I did not know how to ask. Sending this to two other people who asked me the same thing last week.

From the other side of the consultation, briefly.

Reconstitution tip for anyone mixing dosing arithmetic from lyophilized powder: use bacteriostatic water, NOT sterile water. The benzyl alcohol in BAC water preserves multi-dose vials for up to 28 days.

Inject the water slowly down the side of the vial. NEVER shake — gentle swirling only until fully dissolved. Should be crystal clear with no particles.

Closing the loop on my own question.

The bulks-list asymmetry was the piece I had missed entirely. It explains why one of my two pharmacies is still arguing it can supply and the other simply stopped.