Biotin is a B-complex vitamin (B-7) and I've always been told that it's best to take B vitamins in the morning or sometime during the day. I take mine in the late morning as I take a multi at night, and I like to spread the vitamin intake throughout the day. That's just me, though.
I think that the amount you're taking is fine, but be on the lookout for skin issues or mood changes and adjust accordingly. If you take any sort of medication, read about any possible interactions.
Here is a good link - http://www.nlm.nih.gov/medlineplus/d...nt-biotin.html
ETA: The link does not have information about mood changes with taking biotin. I only suggest this because I'm personally someone who notices mood swings when I switch around levels of vitamins or supplements. I'm also on medication that can be affected by supplements, which in turn affects my moods. Just a heads up.