Singapore: Leading global contract research giant Quintiles has cited a challenging external business environment as the reason for shutting down its phase I unit in Hyderabad, India.

The company's spokesperson Phil Bridges has said in a media statement that the unit closed on September 30 this year and about 20 employees working at the Indian facility were given the option to switch to another job at Quintiles.

Mr Bridges said, "Quintiles continues its clinical work in India. This will not impact any of our other early-stage clinical development operations. We continue to operate our clinical pharmacology units in London and Overland Park, Kansas, as well as partner sites in the USA, EU and Asia, and are well-positioned to provide a full suite of early clinical development solutions to customers."

The phase I unit was a joint venture with the Apollo Hospitals Enterprise and had been operational since January 2011.

As per the list released by India's Central Drugs Standards Control Organization, four of Quintiles' clinical trials are under review in the country.