I was working in a college job for a pharmaceutical distributor when the New England Compounding Center outbreak happened. I think that dropped a nuke on the whole industry. We stopped dealing with compounding pharmacies after that because that whole thing was more like a matter of when not if.
I'm most familiar with them for off label ocular injections. Avastin is a common medication for colorectal cancer, but has an extremely similar biologic to Lucentis, used of ocular injections. Compounding pharmacies will breakdown Avastin because it is cheaper than Lucentis, and pre-fill disposable syringes.