Truthfully, anything can be injected. In general, introducing any kind of foreign substance directly into our bloodstream is a major violation of nearly all of our body's time honored mechanisms of preventing infection. As a general rule, injection of pills like this leads to significantly higher levels of severe complication than injecting your standard water-soluble street drugs like Heroin. I know at least half a dozen people from the online community who have had limbs/hands amputated, several who have contracted endocarditis (some repeatedly, ER staff loves that shit) and more than a few who are now dead because they were willing to wager too much on a stupid rush.
Don't get me wrong. Everyday is full of choices and mistakes that we make, but part of surviving means constantly weighing the risks we take with ourselves. An intelligent, reasonable conclusion to this situation sees you ingesting the Amphetamine pill by any route other than injection and enjoying the buzz without freaking out about having potentially maimed yourself. You could have the best of both worlds my friend.
It ain't worth it. Don't do it. Point blank.