I was doing my sisters washing and she is 17 and I found a tablet which I don't reckonize and I was wondering if you could help it is red and yellow with some of the words saying edoxil and its 500 mg and it has powder in it and I have concerns as her behaviour has been rather odd thank you

Try this website:
Pill Identifier - Drugs.com (http://www.drugs.com/pill_identification.html)

International brand for an antibiotic. Perhaps she recently had a surgery/dental work/or has had an infection of some sort?

Doesn't sound like its illegal
Try asking her
(not in an accusing way though)

Actually never mind
I didn't see that she was 17
Not being stereotypical but I
Don't think seventeen year olds can get drugs the legal way
Except for tylenol and stuff
And if its legal your parents should know about it