I say apply once you have most all of the prereq's done, but continue on a path that leads to a B.S. If you get into pharmacy school, just leave your program and that's that. If you don't get in, continue on and reapply each year, and by the end year 4...you'll have a B.S.
if you have 2 more years of HS left, just apply to a 0-6 school. It's a school that will guarantee you a spot in their program if u complete first two years of ur prereqs there.... google usc and uop in cali... It's honestly best way to go... Don't stop there, there are other out of state schools that have similar programs...