The probe into the safety of certain doses of Baxter’s heparin has taken on another slant with the news that the facility in China where the blood-thinning agent is produced has not been inspected by US regulators.

Earlier this week Baxter temporarily stopped manufacturing multiple-dose vials of heparin due to reports of an increase in serious allergic reactions and low blood pressure in patients who receive high ‘bolus’ doses of the drug. However, a report in the Wall Street Journal focuses on the fact that the Chinese facility has not been checked by the US Food and Drug Administration so a problem at that level cannot be ruled out.

The WSJ quotes an agency spokeswoman as saying that "while no FDA inspection of the facility has been conducted to date, preparations are being made to perform an inspection as soon as possible”. She added that the plant making the active ingredient "was supposed to be inspected" but "our understanding is that, due to human error, and inadequate information technology systems, a pre-approval inspection, which would normally be conducted, was not."

The case reignites the debate about the FDA’s ability to ensure the safety and quality of imported drugs to the USA. Recent testimony from the Government Accountability Office said that the agency can only inspect around 7% of foreign drug-making facilities in a given year, and it would take the agency more than 13 years at that rate to inspect all the plants.

China is now the world's largest producer of active pharmaceutical ingredients and in 2005, it had 14% of the world's $31 billion market, according to a report last year from Credit Suisse.