You don't say if you are injecting so-called normal Oxy solution (which is clear - no color to it), or if you are injecting concentrate - which has a gold to orange tinge to the solution color(?).
I use approx 1 bottle of concentrate per week, which is 10mg of Oxy in 1ml of solution (each bottle holds 120ml, or 1200mg of Oxy in solution), and sometimes as much as 2 bottles per week. I have on occassion IV'd this, but other than for a very fast "hit" or "buzz" I found little to no benefit from doing so - the stuff just metabolizes out of your system so much faster than when taken orally.
One of the unique characteristics to taking Oxy orally is it's ability to avoid first pass metabolism, versus say, taking morphine
(sulphate) orally. In taking MS orally you will experience as much as 2/3rds of the dose you take been lost by way of first pass metabolism, whereas by contrast Oxy taken orally, you might loose as much as 25% at most, but more typically around 15% - 20%.
Another way of putting this: while there are advantages to IV'ing MS, there is little benefit in IV'ing Oxy as the bio-avalibility remains much the same as when taken orally.
That all aside, IV'ing liquid Oxy is for sure going to be safer than IV'ing crushed and filtered tabs - at least from a vascular damage perspective, as you are injecting a liquid. There is nothing in the make up of either normal Oxy solution, or the concentrate, from what I can establish which is going to precipitate out of solution in either your veins, liver or kidneys - so you are okay on that score, but from a long term toxicology perspective ......... mmmmmm, I'm not at all sure one way or the other.