Indivior PLC on Thursday said its US unit Indivior Inc has filed lawsuits against Dr. Reddy’s Laboratories Ltd, Actavis Generics, Par Pharmaceutical, Alvogen Pharmaceutical and Teva Pharmaceutical Industries Ltd for infringing US patents for the company’s Suboxone sublingual film product.

The UK listed pharmaceuticals company has filed lawsuits for infringement of US Patent No. 9,855,221 relating to the proposed generic versions being made Dr. Reddy’s, Actavis, Par, Alvogen and Teva of Indivior’s Suboxone film product.

“The lawsuits allege that the aforementioned companies infringe the ‘221 patent, which was issued on January 2, 2018, and is listed in the FDA’s Orange Book. The ‘221 patent relates to certain polymer film compositions having a substantially uniform distribution of the active drug,” the company said.

Indivior has been involved in patent infringement litigation involving other, earlier issued patents covering Suboxone film with the same companies relating to their proposed generic products.

“We continue to partner with Aquestive Therapeutics to innovate and generate new intellectual property around Suboxone film. We believe this new patent is strong and we are asserting it in order to protect our intellectual property rights,” said Indivior Chief Executive Shaun Thaxter.