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ForumsCompounding & FormulationNeedle gauge and dead space — need advice Page 3

Needle gauge and dead space — need advice

sarah_TO Wed, Jun 26, 2024 at 2:36 AM 14 replies 2,007 viewsPage 3 of 3
tom_AK
New Member
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Jan 2026
Anchorage, AK
Jun 27, 2024 at 9:18 PM#11
DebRD_ATL said:
Concentration choice is a precision decision, not a preference.

This answered a question I did not know how to ask.

25 0steve_okc, dave_SLC, FDA_TrackerJim and 22 others
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JenPlateau
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Nov 2024
Missouri
Jun 29, 2024 at 5:17 AM#12

Clinical perspective, offered as context rather than as advice.

Comparison of compounded dosing arithmetic delivery formats I've tried:

FormatProsCons
Lyophilized vialLongest shelf life, lowest costRequires reconstitution
Pre-mixed vialReady to draw upShorter shelf life (28-45 days)
Pre-filled syringesMost convenientHigher cost, shorter shelf life
Sublingual dropsNo needlesLower bioavailability, less data

I use lyophilized vials for cost and stability. The reconstitution takes 30 seconds once you've done it a few times.

24 24TrialNerd_Beth, HPLC_Greg, LibrarianMeg and 21 others
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PharmD_Rodriguez
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Miami, FL
Jun 30, 2024 at 1:16 PM#13
newstart_MO said:
Sharing my dosing arithmetic titration experience with compounded semaglutide — I have been tracking injection volumes meticulously: Using 5mg/2mL…

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.

23 23robert_kc, dan_philly, MeganSA_TX and 20 others
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Dr.GutHealth
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Mar 2024
Minnesota
Jul 1, 2024 at 9:16 PM#14
sarah_TO said:
Dead space is the answer to the missing dose.

Peptide calculator app recommendation for dosing arithmetic: I use PeptideCalc 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.

22 22Dr.RaviCardio, jennifer_SEA, tyler_CSCS and 19 others
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mike_mod
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Jul 3, 2024 at 5:17 AM#15

Moderator note: leaving this open. It is being argued well and the disagreement is the useful part. No action needed from anybody.

21 21PurityPaulOR, MaxMetOK, MounjBrad and 18 others
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