University of Pittsburgh offers MSPBA program for people who wish to get involved in business aspect of things. It is a short program, but can be your ticket to many opportunities.
There are a lot of pharmacy business knowledge, but much are self learned. If you can pin point what you like to know: supply chain, CMS, patient assistance, recall, shortage management, PBM, reimbursement, compliance, 340B......
ASHP has a few books to talk about the topics above.