AstraZeneca Pharmaceuticals LP has again sued Torrent Pharmaceuticals Ltd. over efforts to produce a copycat version of schizophrenia treatment Seroquel XR®, claiming that the generics maker's abbreviated new drug application (ANDA) for a lower strength of the drug also infringes a patent. AstraZeneca lodged filed suit Tuesday in the U.S. District Court for the District of New Jersey, seeking to block India-based Torrent and its U.S. subsidiary Torrent Inc. from manufacturing a 50 mg strength version of generic Seroquel XR® before U.S. Patent Number 5,948,437 expires in May 2017. The '437 patent, titled “Pharmaceutical compositions using thiazepine,” was issued in September 1999 and claims sustained release formulations of quetiapine fumarate, the active ingredient in Seroquel XR, as well as processes for preparing and using such formulations, according to the complaint. AstraZeneca is represented by Finnegan.