Heparin and Heparan sulfates. Source: University of Toronto

The Chinese factory involved in the production of possibly-tainted Baxter Healthcare’s heparin was not inspected by the FDA because of a paperwork error in which regulators confused the factory's name with another that already had U.S. approval, the Chicago Tribune reported.

Last week, the FDA recommended that Baxter temporarily stop manufacturing multiple-dose vials of the injectable blood-thinning drug heparin due to more than 300 reports of serious to deadly allergic reactions and hypotension in patients who receive high bolus doses of the drug.

Heparin has an ingredient produced in China for Deerfield, Ill.-based Baxter by Scientific Protein Laboratories of Waunakee, Wis., according to the Tribune.

While the cause of the allergic reactions remains unknown, the Tribune said the FDA said it plans to visit the Chinese plant this week as part of an investigation that the agency deemed as a top priority.

Joseph Famulare, deputy director of compliance for the FDA's center for drug evaluation and research, portrayed the failure to inspect the Chinese plant as a record-keeping glitch, thus an "isolated incident." However, the agency acknowledged that there is no law requiring that every foreign plant producing U.S. pharmaceuticals be inspected by the FDA.

The FDA said it typically inspects foreign plants as a matter of policy before they begin producing active pharmaceutical ingredients, but the agency "is not specifically required by law to inspect a foreign drug manufacturing facility," FDA spokeswoman Karen Riley told the Tribune.

The FDA also said it inspected 250 foreign pharmaceutical ingredient manufacturers last year, 13 of which were in China.

In the wake of Baxter's problems, APP Pharmaceuticals is trying to increase its production of heparin. APP also gets the active pharmaceutical ingredient to make its blood thinner from a Chinese supplier.

The FDA and China’s SFDA have inspected APP's Chinese supplier, according to the Schaumberg, Ill.-based company.

The company has instituted a direct shipment program to control the distribution and expedite delivery of the products to physicians and patients in urgent need of therapeutic heparin.