(Xinhua)
Updated: 2008-03-16 22:01

BEIJING - China and the United States are in close cooperation in the investigation into a suspect problematic ingredient of heparin products, but no results are available yet, said a Chinese official on Sunday.

Wu Zhen, vice head of the State Food and Drug Administration (SFDA), made this remark while responding to an AP reporter at a press conference during the annual full session of China's top legislature.

It is reported that heparin blood-thinner products, with a suspiciously contaminated ingredient from a supplier in Changzhou, east China's Jiangsu Province, have caused serious reactions and deaths in the United States.

The US Food and Drug Administration (FDA) has sent work staff here for inspection, receiving active support from China, Wu said.

Both sides have spot-checked the samples and scientists from the two sides have conducted lab tests, but no precise conclusion is available yet, he said, adding the investigation is still going on.

He promised to inform the public of the conclusion as soon as the investigation results come out.

He also pointed out that the Changzhou factory is just one link in a long production chain, and "it's still not clear whether the problem is in raw materials or in overseas production."

The chain also involves the Changzhou factory's share-holder Scientific Protein Laboratories (SPL), which imports the raw heparin from the Chinese factory and then supplies the ingredient to Baxter International, one of the major heparin producers in the United States, he explained.

Wu's administration announced last Friday the latest progress of the joint investigation, saying China's National Institute for the Control of Pharmaceutical and Biological Products had adopted the USP's criteria to test samples of raw heparin from the Changzhou factory and found them all up to standard.

The Changzhou factory, a chemical plant but not a drugmaker, is not registered within the SFDA and its raw heparin is subjected to quality checks both by itself and SPL, the administration said.

It is reported earlier that FDA detected suspicious contaminant in raw heparin from the Changzhou factory by using "non-standard" drug-purity test, but FDA is not certain that the contaminant is to blame for the allergic reactions.

China now has 23 registered raw heparin suppliers, with some sheer for exports.