The Indian government has introduced new patents legislation in parliament to stop local firms producing cheap generic versions of patented drugs.
Critics say medicines will be more expensive in the future
The controversial bill is aimed at making India compliant with World Trade Organisation (WTO) rules.
Opponents of the bill fear that India's lucrative share of the global generic market may fall drastically if it becomes law.
India has about one-sixth of the $48bn global market for generic medicines.
Under the proposed law, the government would have to grant patents for all new products developed after 1995.
India only grants patents on the process of manufacture at present, rather than on the final product.
Firms have been able to use different processes to produce medicines introduced by international competitors and then sell them at less than half the price, thus making huge profits.
Opposition members in the parliament said that the new law would raise the prices of medicines and push small and medium-sized local firms out of business.
Government officials dismiss these fears, arguing that it is more important for the country to honour international commitments.
"It does not speak well of a country that boasts of a billion-plus population and has the third largest manpower pool of research and development," TK Bhaumick, a consultant with the Confederation of Indian Industry, the AFP news agency reports.
"Why should it be afraid? Indian firms can handle the challenge," he said.
Mr Bhaumick was similarly dismissive of apprehensions regarding a possible rise in prices.
"Many of the patents on blockbuster drugs have expired. The proposed law will not affect the pricing of the majority of drugs," he says.
But the reservations regarding the new law do not come from the opposition alone.
Several developing nations are worried that the proposed patents law may make Indian-manufactured generic medicines for those battling HIV more expensive, AFP says.
But Indian officials say HIV patients will not suffer as WTO regulations would still allow Indian firms to ship drugs to those countries that do not have indigenous manufacturing facilities.
The Indian pharmaceutical sector has done well under the old process patent regime.