When I first entered college, my major was Chemistry for pre-pharmacy program. I ended up just sticking with chemistry and eventually completely changed paths and ended up in business. I did not consider biochemistry much at the time, but from what I know now, I think Chemistry still provides as solid a background. It also likely opens more career options should your pharmacy plans change, or look to do more. Ultimately, it is a personal decision for how you want to prepare for your program. Look at the curriculum and see what matches best with the programs that you're looking to be accepted. I believe that Chemistry has more biology and mathematics than Biochemistry has chemistry and mathematics. Good luck!