New Delhi, March 15 -- Despite the latest US Food and Drug Administration's ( US FDA's) stricture on one of its plants, Lupin Ltd's stock didn't react negatively. The stock was up marginally at Rs.764.20 on Thursday. The US drug regulator classified the inspection of the company's Mandideep (Unit 1) plantin Madhya Pradesh as "official action indicated". This implies a possible freeze on approvals of new products from the plant. Given that no new filings from this plant are pending, the observation will not have a noticeable impact in the immediate future....