Can you be legally charged to drugs found on the highway 45days after you were pulled over,searched,and released? Aren't there statues of limitation?also, isn't is just unfair?

Depends on the state you live in, the statue of limitation may run from 1 year to 5 years or more depending on where this is, and the amount of the drugs.

But 45 days is not even time, I am surprised they got the drug tests done in that short time.

But of course they can arrest you just that long out. That is considered fast in many areas.