Math is hard - help me with reconstitution please

PeptideChemSF said:

Concentration choice is a precision decision, not a preference.

I am going to disagree with reconstituting low as a general rule. More diluent, more punctures, more in-use days at room temperature, and the stability trade-off is real. Precision is not the only variable being optimised.

WendyG_ATL said:

I reconstituted a 10mg vial with 2ml of bacteriostatic water and I want someone to check my unit arithmetic before I draw anything, because I keep…

Just received my dosing arithmetic order — packaging review:

• Outer box: plain brown, no medication identifiers (discreet) ✅
• Inner insulation: Styrofoam with 4 gel ice packs ✅
• Temperature: vials were cold to touch on arrival ✅
• Labeling: lot number, BUD, compound name, concentration ✅
• Included: COA, reconstitution instructions, dosing card ✅

This is what professional compounding pharmacy shipping looks like. If your order arrives without these basics, reconsider your vendor.

DebRD_ATL said:

I am going to disagree with reconstituting low as a general rule.

Bacteriostatic water quality matters for dosing arithmetic reconstitution. Not all BAC water is created equal:

• Should contain 0.9% benzyl alcohol as preservative
• Must be sterile and pyrogen-free
• Should come in a sealed, intact vial
• Check expiration date — yes, BAC water expires
• Store at room temperature, protected from light

I buy from a reputable medical supply company, not Amazon marketplace sellers. The $3 savings isn't worth the infection risk from unverified BAC water.

Following on from DeniseRN_TPA — and this may be the naive question:

How much material I am losing to dead space, and whether that explains why a 10mg vial gives me nine usable draws rather than ten?

Closing the loop on my own question.

Follow-up: it was dead space. Switching to a low-dead-space fixed-needle syringe gave me the tenth dose back.