When choosing a recommendation letter writer, here are some things I'd personally consider:
- Is this person aware of your interest in pharmacy and the schools you're applying to?
- Can this person evaluate your potential as a pharmacist?
- Is this individual capable of discussing your personal characteristics?
- Can they discuss your leadership skills, your ability to work with others, professionalism, and your academic skills (whether you can succeed in a graduate program)?
It also helps to ask your recommendation writer to sit down with you and talk about your interests in applying to pharmacy schools. This gives you a chance to help your letter writer answer some of the previously mentioned questions. Most importantly, I'd suggest you always pick the person who has things to SAY about you - not the one who will just check the boxes and write nothing else beyond that. Good luck!
To add to that thread and this one, the ideal letter will have good articulations about your abilities. An excellent pharmacist and/or professor may look nice at face value but a generic letter can wipe that out. In a pile of hundreds of LORs, a good LOR helps make your application stand out more.
I'd say that in addition to the excellent advice from justyliz, try getting a professor that knows you for "you" and more than just another face in lecture. Chances are better your app will stick out if your LOR writer knows your funny qwirks and outstanding merits. If anything, try a research or volunteer coordinator/mentor. Best of luck in your endeavors!