well....
there really is no way to know for sure... If you're paranoid (like me), then you could:
1) Buy some sterile glass vials, and some 0.45 micron or 0.22 micron syringe filters
2) syringe filter the contents of your shampoo bottle into the glass vials
3) heat the glass vials in boiling water for 10-20 minutes (water about half way up the vial, don't let the rubber stopper on top get wet)
That should kill whatever might be in there. Of course some people will call this overkill, but like I said, I'm a paranoid fuck who won't inject just anything deep into my body.
Just a thought.
DrG
PS: next time, get a sterile saline bottle.