The FDA believes that the heparin is contaminated with over-sulfated chondroitin sulfate (OSCS), which originated in China and entered the US before import controls were established in response to the crisis.
Letters were sent to Celsus by the FDA in April and May, informing the company that its actions to inform customers of the contamination were insufficient to assure an effective recall.
Consequently the FDA deemed it necessary for the contaminated lots to be seized. US Marshals took five lots of heparin sodium active pharmaceutical ingredient (API), used in finished drug products, and six lots of heparin lithium, used in medical devices.
The lots of API seized amounted to just over two pounds, with a further 31 pounds intended for use in medical devices. Celsus had quarantined the affected lots since April, according to media reports.
It is rare for the FDA to initiate the seizure of products, suggesting that the agency was unable to resolve the dispute through dialogue.
The FDA has been seeking for companies to physically recall potentially contaminated batches of heparin as it attempts to minimise the harm to patients and the agency’s reputation.
To ensure the product is not administered to patients the FDA is advising manufacturers who may have purchased heparin from Celsus to check with the company that their batches are not contaminated.