Is a Fentanyl 100 mcg patch and a duragesic 100mcg patch the same dosage?

No - they are 2 completely separate drugs. OxyContin is the time release version of Oxycodone, and typically lasts from 7-12 hours.

Duragesic / Fentanyl transdermal patches are timed release fentanyl over a 48-72 hour period. Its release is regulated by body heat. It is a much more reliable and steadier drug than OxyContin, in that it doesn't wear off as fast, and it lasts a lot longer.