Biotin is a water soluble supplement so you can take it whenever you want. If it were fat soluble you would be better off taking it with your biggest meal of the day. I have been taking biotin for my nails for the last year and a half and just take it whenever I think about it. I always have some sort of medicine to take each day so I take that at the same time.
And as long as I've been taking it I've not had any problems with acne. Don't know that I've noticed any difference with my hair but I was taking if for my nails so that's really the only thing I paid attention to.