air bubble in b12 injection How to Give a Injection: Step-By-Step Instructions Air Bubble in IV Line
Description
Some patients also experience mild diarrhea, swelling, or itching

For example, injectable pyridoxine solutions may contain aluminum as a trace impurity, and with prolonged use in patients with renal impairment (especially premature neonates with immature kidneys) there is a risk of aluminum accumulation and toxicity

I definitely advise possibly going to a dermatologist if possible
If you have not had low B12 confirmed, that check with your GP comes first
Packaging container: Amber Glass Made Multi-Dose Vial-Picture Courtesy: Vet-N-Pet DIRECT Multi-dose vials are used to dispense vitamin b12 injection for dogs and these vials contain preservatives to avoid instability in formulation

B12 appears in animal foods and fortified products
