We bought an egg incubator from Tractor Supply (yee-haw) and we keep it at a steady temperature and it keeps it from crystallizing, it's become our "bin" for Mannitol and we keep 2-3 bags in there as well.
We keep it about 2 degrees below the maximum recommended storage temperature. As long as people aren't in and out of it too much, it does the job and saves the time of having to do the warm water...
We use a Winthrop Pharmaceutical contrast media warmer
We have had it for years, it will keep up to 12 bags
and we can fit 2 cases of mannitol vials in it. Our hospital is in South Dakota so in the winter almost
all of our mannitol is crystalized when we get it.
We send any vials that have crystalizing over to sterile processing and in a very short time they return them good as new. We keep all of our vials in a hot box with the light bulb like others have said and that usually is all it takes. We don't have very many that ever need any attention.
I appreciate all of your input on the many ways to de-crystalize my mannitol. I finially went to the farm supply store as Colleen suggested and got an egg incubator, thank you Colleen. It works great!!!