I can add this to the conversation,wrt the pharmacy I have used for over a decade.In our Files under Canadian Sources.
It is from 2010 (I had asked about it back then), but my understanding is that testing is done on a regular basis:
"In November, 2010, Island Pharmacy ( then known as Shawnigan Lake People's Pharmacy ), B.C., sent 15 capsules from 2 lots of Pergolide Mesylate powder, to the lab for analysis, covering the powder that had been used over the last 6 months. They also sent both new and old capsules (capsulated for 3 months) The lab results said they were stable and compounded 1mg Pergolide Mesylate capsules with a measured 0.949mg/cap which is where the USP guidelines says it should be for compounded medication. "
Lorna in Eastern Ontario, Canada