Officials for the United States met with the Chinese regarding the origin of the tainted heparin that sparked a rash of allergic reactions and several dozen US deaths lately but failed to reach an agreement as to where the contaminant in the drug actually came from and whether the contaminant did, in fact, cause the adverse reactions.

The US says the contaminant, oversulfated chondroitin, came from Chinese raw ingredients and did cause the allergic reactions. China says no. China claims the oversulfated chondroitin did not cause the reactions and did not originate in China.

The US and 11 other nations discovered the contaminant in raw ingredients that came from the Changzhou SPL Company Ltd., the Chinese processing plant for the Wisconsin-based Scientific Protein Laboratories (SPL). Officials from China and all 12 nations affected with contaminated heparin met with officials from the US Food and Drug Administration (FDA) behind closed doors several days ago. The result of that meeting is an FDA warning letter issued today.

The letter claims the equipment used at the Changzhou plant is not used as intended and the supply chain is not properly inspected or evaluated from the raw ingredient’s origin as intestines from pigs raised on thousands of rural farms. Heparin shipments from the plant to the US began in 2004 although the plant has not been inspected by Chinese officials or by the US FDA.

China hasn’t inspected the plant because it is classified as a producer of chemicals, not pharmaceuticals. The FDA claims to have tried to inspect the plant once but confusion between it and another, similarly named, facility resulted in no inspection.

Some of the heparin allergic reactions were linked to Baxter International, a drug maker that buys raw ingredients from SPL. Jin Shaohong, deputy director-general for the National Institute for the Control of Pharmaceutical and Biological Products in China, announced today that Chinese officials will be touring the Baxter facilities tomorrow, with the intent of securing samples to undergo an independent, in-depth investigation and analysis in China.

The continuing saga of the tainted heparin has spotlighted the inadequate regulations the FDA places on imported drugs or drug ingredients and the fact that it is currently overburdened and underfunded. Congressional members have called for greater control measures, in order to ensure the same standards for foreign-made pharmaceuticals meets the same exacting standards as US-made drugs do.

Jin says Chinese officials do not support the idea that the point of origin for the adverse allergic reactions is the oversulfated chondroitin but says that the Chinese are eagerly awaiting the determination of the source of the problem. The FDA announced the impending opening of its first office ever in China.