Cadila Healthcare Ltd said it has received a warning from US health regulators for violating manufacturing standards at two production sites in India, sending its shares down 17 per cent to its biggest single-day percentage fall.
The letter from the US Food and Drug Administration cites issues at Cadila's plants in Gujarat: the Moraiya drug production site and another in Ahmedabad city where it makes drug ingredients.
The warning for Moraiya comes more than a year after the FDA inspected the plant in September 2014, and issued a report highlighting a series of problems. Cadila said in October its work to fix the issues was complete.
But it has not received US approvals for drugs made at the plant for a year, causing it to miss the launch of a key drug, Asacol HD, in November.
On Thursday, Cadila said in a statement that it was "committed to resolve all the issues and revamp our quality systems and processes as the top most priority."
It was not immediately clear how much the Moraiya site contributes to Cadila's sales, but analysts have said getting the plant back on track is key for the company.
Cadila said none of its products being sold in the US used any raw materials made at the Ahmedabad plant.