In its ongoing patent litigation over cholesterol lowering drug atorvastatin (Lipitor) against India's Ranbaxy Laboratories [Get Quote], Pfizer [Get Quote] said on Tuesday in a court in Ireland had ruled in its favour.

The world's largest drugmaker said in a statement that the high court in Dublin had ruled that the basic patent covering atorvastatin -- the active ingredient in Lipitor-- would be infringed by Ranbaxy's generic product.

"The decision, which is subject to a possible appeal, prevents Ranbaxy from launching its drug before the basic Lipitor patent expires in November 2011," the Pfizer statement said.

"We remain confident of our position and will file a timely appeal," Ranbaxy spokesperson said. Pfizer General Counsel Allen Waxman said: "Today's decision is yet another affirmation of the strength of the intellectual property behind Lipitor."

It is also an important outcome for Pfizer and other medical innovations who invest in high-risk research to develop life saving medicines, and for the patients who benefit from these medicines, he added.