A while ago I posted that hydroxocobalamin for injections contains only water, sodium chloride and acetic acid (water, salt and vinegar). Since then I've read a couple of times that there is other gubbins in there that can cause a reaction. So I dug further. Here's the list of excipients (posh term for 'other gubbins apart from B12') in the two I use....
Vitamin B12 Depot Hevert (from amazon.de)
Water, sodium chloride, acetic acid, sodium acetate
Cobalin-H (from the NHS)
Water, sodium dihydrogen orthophosphate, sodium chloride, sodium hydroxide (for pH control), hydrochloric acid (for pH control).
Sodium dihydrogen orthophosphate is a common food additive (E339) - food-info.net/uk/e/e339.htm - and is GRAS (generally recognised as safe). In this case it is used as an acidity regulator. Along with the sodium hydroxide and hydrochloric acid it will keep the pH stable (known in chemistry as a 'buffer').
The acetic acid / sodium acetate combination will perform the same function. Both compounds are extremely common in the human body.
Here are some others I found -
Hydroxocobalamin 1mg in 1ml solution for injection. Auden Mckenzie (Pharma Division) Ltd
Water acetic acid, sodium chloride, sodium hydroxide
Hydroxocobalamin Injection BP. Amdipharm Mercury Company Limited
Water, glacial acetic acid, sodium chloride
I have found a couple of old, American, sites that, in addition to the water, acetic acid and sodium chloride, include methylparaben and propylparaben as preservatives. Since 2010 the European Medicines Agency has been investigating the use of parabens in medicines and it doesn't look good for them - ema.europa.eu/docs/en_GB/do...
In a situation like this the companies making hydroxocobalamin for injections are likely to stop using the stuff voluntarily, rather than getting slapped with a sudden ban which stops their production. I've looked long and hard for European companies using parabens with no luck.
It will be interesting to see if the reports of adverse effects from B12 injections reduces.