The US regulator, which visited the drug manufacturing facility in December last year, said Nippon’s quality control manager had “directed employees to stand shoulder-to-shoulder, barring our investigator from accessing portions of the laboratory and the equipment.”
The Food and Drug Administration (FDA) also said Nippon had refused to provide inspectors with copies of customer complaints and prevented them from taking photographs of equipment used to make drugs for the US market.
The FDA said: “Until FDA is permitted to inspect your facility and confirms compliance with CGMP, this office may recommend withholding approval of any new applications or supplements listing your firm as a drug manufacturer.”
Nippon was placed on the agency’s import alert list in August, which prevents products made by the firm from entering the US.
The Japanese drug and fine chemical firm did not respond to a request for comment.
According to its website Nippon makes the cough suppressant camphor, phospholipids and other intermediates for the drug industry, both domestic and international.
The Takasago site houses a pilot plant and a clinical trial drug production area.
The firm also states its facility has been inspected by Novartis, Abbott, Gilead and Eisai among other pharmaceutical companies.