Shares of Dr Reddy's Labs hit 2-1/2-year low on USFDA observations.

The stock fell as much as 4.21 per cent to its lowest since August 13, 2014.

The US Food and Drug Administration has completed the audit of drugmaker's formulation manufacturing unit near Vishakapatnam in Andhra Pradesh, according to an exchange filing on Wednesday.

USFDA has issued form 483 with 13 observations for Vishakapatnam facility.

An FDA Form 483 is issued to companies when the inspection ends, when the investigator has observed conditions that may constitute violations of the Food Drug and Cosmetic Act.

As of Wednesday's close, the stock was down 7 per cent this year compared with a 9 per cent increase in the broader NSE index.