NEW YORK (AP) — Warner Chilcott Ltd. said Monday it received notification that Lupin Pharmaceuticals Inc. asked the FDA to approve generic versions of the oral contraceptives Loestrin 24 FE and Femcon FE. The notifications, called Paragraph IV Certification Notices, signal a company’s intent to make a generic version of a drug. Often, the notifications signal a patent challenge when the drug being referenced still has a substantial amount of time until its key patents expire. Ireland-based Warner Chilcott said it started selling Loestrin 24 FE in March of 2006 and patents don’t expire on the drug until 2014. Meanwhile, it started selling Femcon FE in 2006 and a key patent for that drug doesn’t expire until 2019. Loestrin 24 FE had $52.4 million in sales during Warner Chilcott’s first quarter, while combined sales of all the company’s oral contraceptives reached $73.1 million. Lupin Pharmaceuticals is the U.S. wholly owned subisidiary of Lupin Ltd., a drug development company based in Mumbia, India. Lupin Pharmaceuticals has its sales and marketing headquarters in Baltimore.