Dr. Reddy's Laboratories Ltd, the Indian generics major, who lost a patent litigation against Prilosec inventor AstraZeneca in a US court, has decided to file an appeal against the court's decision on two formulation patents.

Judge Barbara Jones had ruled that both the formulation patents were valid and that Dr. Reddy's, Genpharm Inc., an affiliate of Merck KGaA, Germany and Andrx Corporation infringed both the patents. KUDCo, a wholly-owned subsidiary of Schwarz Pharma, was found not to have infringed either of the patents.

The case originally commenced with AstraZeneca's suit on seven patents. Of these seven patents, Judge Jones found one patent concerning a metabolite of omeprazole to be not infringed, and found three patents covering particular uses, or therapies, of omeprazole to be invalid. One patent, covering the basic compound, expired last year.