I've had my 2-CE for about 2 months and it still seems quite fresh; I've been keeping it in the zipper-bag that it came in...however, I would recommend storing it in a baggie, inside a brown/black light-resistant pill bottle. This will keep it away from air, moisture and light; keeping in a cool place, such a refrigerator or freezer, will definitely increase the longevity of the compound.
and also can put a dissicant bag(driederite or similar) with the compund bag, both inside the another second zipper bag
