Interactions between doses of medicines I take. Don't want to cause a bad interaction?

I would give it a couple of hours at least. As long as you are taking the prescribed dose per the script or the bottle, I don't see any problem with this. I take all of the drugs you mentioned except for ibuprofen, but I do take aspirin. I cannot take my tizanidine during the day, but I do take it at bedtime. And remember, never ever take your tizanidine with caffeine.