Barr Confirms Patent Challenge of Fentora Tablets

Barr Pharmaceuticals, Inc. today confirmed that its subsidiary, Barr Laboratories, Inc., has initiated a challenge of the patents listed by Cephalon, Inc. in connection with its Fentora(R) Tablets (fentanyl citrate buccal tablets), equivalent to fentanyl base 100 mcg, 400 mcg, 600 mcg and 800 mcg.
Barr filed its Abbreviated New Drug Application (ANDA) containing a paragraph IV certification for a generic Fentora product with the U.S. Food & Drug Administration (FDA) in February 2008. Following receipt of the notice from the FDA that Barr's ANDA had been accepted for filing, Barr notified the New Drug Application (NDA) and patent holder.

The details can be read here.