Compatible But keep in your mind B12 in form of cyanocobalamin or hydroxocobalamin iv no benefit as it run out in urine rapid If you want B12 with benefit iv use Methylcobalamine form.

Physical Compatibility: Physically compatible. No visible haze or particulate formation, color change, or gas evolution.

Citation: Kirkland WD, Jones RW, Ellis JR, et al, “Compatibility studies of parenteral admixtures”, Am J Hosp Pharm, 1961; Volume 18: pp. 694-9.