Generic Drugs From India Prompting Turf Battles
Dr Reddy's Laboratories, Ranbaxy Laboratories and other Indian manufacturers of generic drugs are aggressively challenging patents held by world's largest pharmaceutical companies in bid to expand in $17 billion US generics market; can produce drugs at fraction of what it costs to make them in West and are generating much higher margins in US by being among earliest to enter market when patents expire; are meeting fierce resistance in courts from patent holders, who argue that generics will whittle away incentive to innovate, jeopardize investment in new and much-needed drugs and sacrifice consumer safety; patent holders are also patenting component chemicals and processes in addition to drug itself; photos (M)