I work as a tech in a hospital pharmacy. Right now we have 3 "student techs" who work PRN. Whenever they have a break from pharmacy school they pick up shifts because we are always a little short staffed. One tech was in a similar situation as you and got hired.
If you are leaving in 4 months, you won't get hired for full-time or part-time. All the techs where I work get cross trained on every position, so training alone takes about 1-2 months. If you are coming home for breaks/holidays during pharmacy school, AND the hospital near your house has openings for PRN positions in the pharmacy, you might get hired.
If not, you might want to look into PRN (or per diem) positions at hospitals near the school you will be going to. I feel like a lot of hospitals are short staffed, so if you go to school in an area with a few hospitals it shouldn't be too hard to find one.