Dr Reddy's Laboratories has filed an abbreviated new drug application with the United States Food and Drug Administration for Rabeprazole Sodium Delayed-Release tablets (20mg).

Dr Reddy's said it has notified Eisai, a pharma company, about the ANDA. Eisai had filed a lawsuit against the company in the United States Districts Court, alleging patent infringement on the "552 patent", a DRL release said in Hyderabad on Thursday.

Rabeprazole Sodium is the generic version of Eisai's Aciphex and is indicated for the treatment of gastroesophageal reflux disease and duodenal ulcers.

The brand had annual sales of approximately $ 1.2 billion in the US, the release added.