Bangalore: In the week, when both the Indian bourses ended marginally lower in line with the U.S. market, health care sector emerged as the largest gainer ending 7.11 percent higher. The health care index traded in the range of 4,044.46- 4,309.79 points last week (September 22 - September 25, 2009). Among all the stocks listed under health care index, Dr Reddy's Labs topped the list with a gain of 18 percent followed by Torrent Pharma, Natco Pharma, Piramal Healthcare and Ranbaxy Labs, which surged in the range of 14-17 percent. As per estimates, blockbuster drugs to the tune of $114 billion will go off patent over the next three years. Last week, shares of Piramal Healthcare and Dr Reddy's Labs were in demand after reports suggested that UK-based GlaxoSmithKline was looking for potential acquisitions in the Indian market and shortlisted Piramal Healthcare and Dr Reddy's Labs for the proposed acquisition. India's 35,000 crore drug market, which is expanding by 14-15 percent a year, is another reason for multinationals to look seriously at the pharmaceuticals companies in the country. Among the 13 sector-specific indices of the exchange, health care sector was followed by FMCG sector which ended 1.74 percent higher. On the weaker side, metals index was the largest loser ending 3.87 percent lower and was followed by the IT sector which lost 3.13 percent. As of September 29, 2009, total market capitalization of the health care index was of 158,947.11 crore.