Marksans Pharma today said UK health regulator has issued "certain observations" regarding the company's Goa facility after inspecting it in November.
Shares of the company opened weak at Rs 96.20 before falling 20 per cent to intra-day low of Rs 75.80 and got stuck in the lower circuit limit.
On NSE, the stock opened at Rs 96 and finally settled at Rs 75.70, down 20 per cent.
"The UK Medicines and Healthcare Products Regulatory Agency (MHRA) has conducted a good manufacturing practice (GMP) inspection of the company's plant in Goa in November 2015. Pursuant to the inspection, UK MHRA has issued certain observations which company has responded to," Marksans Pharma said in a regulatory filing.
Meanwhile, the Goa plant is functioning normally and the shipments to the UK are continuing in the normal course of business, the drug firm said.
The company's Goa plant is one of the biggest facilities for soft gelatin capsules and tablets in Asia.