I have used Fentanyl, Sandoz, and Watson brands. Fentanyl with the Myland of course, stays on the best, so I use these in the Summer months. When Winter comes, I switch over to other brands.
I've called Jansen for the Mylan coverings before. The others just said to use some tape or buy the Mylan (Tegaderm) at a Medical Supply place. The cost, I agree is outrageous! If I remember, I think 5 of them runs about $30 or so.
I was wearing the patches every 2 days, but I moved to another State and my new Dr. said OFF with 2 days and changed me to 3 days. I did it with NO problem. Didn't even notice the difference. I have good luck with the patches and pain relief.
They stick the best on my flank area. My upper chest sticks, but if I encounter a day of humidity....forget it. It's lifting on all the edges. I still wear it if it does lift for another day, and don't much notice any withdrawals or pain problems.
If you call Sandoz, they will give you some good ideas on what you can use to help keep it on, and they can tell you where you can wear THEIR patches. I think Sandoz isn't so particular as Duragesic on placement. I've always stuck to flank and chest anyway.