Altaf Ahmed Lal, country head of the US Food and Drug Administration (US FDA) in India, has quit and so have a few other key officials at the American drug regulator's India office.
Sun Pharmaceutical's acquisition of Ranbaxy has received final approvals.
Whistle-blower Dinesh Thakur will speak on Made-in-India drugs at an event in Washington.
Margaret A Hamburg, the first commissioner of the US Food and Drug Administration (US FDA) to visit India officially, will meet heads of major domestic pharma companies such as Ranbaxy, Wockhardt, Cadila Healthcare and Lupin in New Delhi.