Dr. Reddy's Laboratories has filed an Abbreviated New Drug Application (ANDA) with the United States Food and Drug Administration for Rabeprazole Sodium delayed-release tablets, 20 mg, with a paragraph IV certification on the two Orange Book patents listed for the drug.

Dr. Reddy's notified Eisai, upon which the latter filed a lawsuit against the company in the United States District Court for the southern district of New York alleging patent infringement on the 552 patent.

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 in the United States of approximately $ 1.2 billion.