BariatricNurseD said:Dead space is the answer to the missing dose.
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.
Ask again with the specifics and you will get a better answer than this one.
ricardo_MIA 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…
Peptide calculator app recommendation for dosing arithmetic: I use DoseRight to calculate reconstitution volumes and injection doses. Eliminates math errors completely.
Input: vial size (mg), desired concentration (mg/mL), prescribed dose (mg)
Output: BAC water volume (mL), injection volume (units on insulin syringe)
A math error with injectable medication can mean underdosing or overdosing. Use a calculator every time until the math becomes second nature.
Dr.SurgeonPGH 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.
Janoshik Analytical — Independent Testing
Trusted third-party HPLC & mass spectrometry analysis. Verify peptide purity with the lab the community relies on. Independent. Accurate. Transparent.
Verify Your PeptidesGL Biochem (Shanghai) Ltd. — Direct Manufacturer
Est. 1998. The synthesis house behind the vials you send for testing. ISO 9001 and cGMP certified, 1,500+ staff, batch-specific COA with every order.
Browse GL BiochemA narrower follow-up, since the general answer is now clear:
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?
OP back with an update, since a thread like this is useless without one.
Resolved. I wrote mg, ml and mg/ml on the vial in marker and did the division in that order, and the two of us now get the same number every time.