So I just discovered something. Ideal PH for L carnitine is 6.0 . At PH 6.5 and above L carnitine degrades into TMA . With in couple of weeks 5 to 10% of it could become TMA which gets converted into TMAO by liver. TMAO is the reason why most people use L carnitine as prework in first place, it messed up your blood vassals.
This is why most pharma grade L carnitine has a PIP. They are all in PH 5.5 to 6.5 range. Most have PH of 6.0 per specs.
Yeah, it needs to be acidic for long term stability, and the acidity contributes to the pain slightly, but most of the pip is from its osmality or tonicity. There are some injections that are under 6 pH that cause no pain, like buffered NAD for example is 5.3–5.6 pH.
The super high osmality makes it where l-carn injections pull water out of the surrounding tissues. L-carb base is very hygroscopic, if you leave it out, it will end up looking like it melted, but actually it just pulls the water out of the air.
The osmolality of 600mg/ml l-carn is 3720 mOsml/L; human tissue is 280-295 mOsml/L; the highest recommended osmality for IM is around 600 mOsml;
so 600mg/ml l-carn at 3720 mOsml is about ten times the concentration that would be comfortable for IM injection.
That’s why the only pharmaceutical preparations are 200mg/ml; and are indicated for IV use only. They are sold as 1g/5ml amps.
To determine the osmality of something:
1. Determine the molality of the solution
2. Multiply that by the number of particles it disassociates into (for l/catn this is 1)
3. Convert to milliosmoles per L
So divide the concentration in g/L (600mg/ml =6g/L) by the molecular weight (161g/Mol) which equals 3.72Mol/L
Then multiply that by the number of particles that by 1, then convert to milliosmoles by multiplying by 1000, so 3720
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