A few points:
1. From the research doc:
"Another series of tests was performed to determine the length of time methylcobalamin solutions could be left in amber glassware in ambient light. We found, to our surprise, even in amber glassware we have found some breakdown. Also, to our surprise, it isn’t very sensitive to heat. We were able to hold it in the dark at 80oC for several hours with minimal breakdown. It is, however, VERY sensitive to mechanical shock. It cannot be shaken, sonicated, or even rapidly mixed on a magnetic stirring apparatus. It can however, be swirled, slowly stirred, or rocked to help dissolve and mix."
Unfortunately, that's where their research becomes indisictinct. "Some breakdown" in amber glassware doesn't tell us much. The other important point though is the sensitivity to physical shock which becomes relevant when mailing around the world.
The only reason I'm being so critical is that I have experienced a certain B12 that was of very high quality. Unfortunately, I'm left to my own devices to try and find out what it was about that B12 that made it so good. The only thing I really know is that it was in powder form.
2. Are you using Arnika's methylcobalamin? Do you find it to be high quality? If so, perhaps I'll go ahead and order some to try.
3. I suspect that the best solution for me personally is the powder form if I can find it.
Thanks.