Its hard to get 400mg in one cc.It can bed done apparently but how consistently from a 3rd party/underground lab like Valopharm remains to be seen.
I'd STRONGLY reccomend getting some sterile oil and a sterile vial and DILUTING it so it doesn't fucking feel like you were just shot in the ass with a 9mm beretta.
With something that is this concentrated removing the BA will likely cause test to break out of solution (almost certain).
Sterile oil is DIRT cheap.