I'm assuming you're referring to paying for pharm school while in pharm school:
Once you get into pharm school, you'll get your pharm intern license. As a pharm intern, you get paid approx. $15/hour (varies though) for working retail. So depending on how many hours you work, you can get some of your extra expenses out of the way but I doubt you can pay for the entire tuition from working. Well, at least in my case I can't since I owe the school about 35K a year (not including housing, etc). That's where the loans come into the pic... 😀