It can be done, but it cannot be done safely from the point that you're at. The product was never sterile enough to be injected to begin with.
When I say this, I mean the powder that it was made from was never treated with the same care as an injectable is. The likeliness of you getting an infection will skyrocket, especially since it's an ED injection.
We're talking about infections and abcessing here.
Its not worth the risk bro, forget it.
Chris