Okay (just researched this a little bit and found some disturbing information),
The brand name new Opana ER's have a new time release feature unlike the MS Contins or OxyContins, or their generic counterparts. It's called "TIMERx" and silicified microcrystalline cellulose. In other words, it's harder than the Contins to get into liquid form and also has a form of SILICA microcrystalline cellulose in it! Silica is EXTREMELY bad for your veins and EVEN WORSE for your lungs. Silica inhalation in and of itself (even snorting) could be dangerous! I don't really know what silicified microcrystalline cellulose is, but if it has silica in it, it can't be good. This is all in the prescribing information:
http://opana.com/pdfs/Opana_ER_PI.pdf
I'm guessing that this product has been formulated very dangerously for intravenous injection. It's almost like they want you to hurt or kill yourself if you try and inject this pill. It blows my mind that they go to these extreme (and expensive) lengths to try and hurt people trying to get high off of this pill! I don't know if this was their own decision (Endo Pharmaceuticals) or the FDA required this because of the extreme abuse potential of this extreme opiate. I have never tried oxymorphone, but if it's anything like the codeine, hydrocodone, oxycodone wave, it would have to be better than hydromorphone and that's hard to imagine. Almost like a rush more intense than heroin or hydromorphone and twice as dangerous. Anybody ever had Numorphan IV in the hospital? Just wondering if this oxymorphone gives a rush when IV'd greater than hydromorphone.
I'd hold back on injecting until further research is done. This is a new product and a new time release feature...