While the patent on the chemical drug expired in 2015, Teva obtained new US patents covering pharmaceutical formulations for long-acting delivery. Litigation from industry competitors in 2016-2017 resulted in the new patents being judged invalid.
The expiration of the patent on the chemical medication led to Teva acquiring new US patents covering prolonged-release pharmaceutical formulations. Nevertheless, litigation from industry rivals in 2016-2017 rendered the new patents invalid.