if you are desperate to inject it somehow, i would either get some help with an IV injection, or make sure you use sterile water and supplies along with a micron filter before you IM it, but even then there are risks like they said above.
but if your talking about percs(oxy w/ tylenol) i definitely wouldnt even bother with any sort of injection. its just not worth it, but if you have the OC's or something with pretty much only oxy as the active ingredient, then its possible to do it, but you could very easily get an abscess. even when a doctor gives an IM injection its possible to have complications
and as said before, swallowing it or plugging it would work very well. it just probably wont give you a rush. if your intolerant than you might get a rush after plugging or maybe oral but you should atleast get really high.
overall, dont do it.....there are much better/safer options and risking a limb isnt worth it.