Scientists create small amounts of safer heparin

LONDON, Aug 18 (Reuters) - Scientists have created tiny amounts of a fully synthetic version of the drug heparin in a move that may avoid the risk of contamination, blamed for the death of more than 80 U.S. patients earlier this year.

So far, Robert Linhardt and colleagues at the U.S.-based Rensselaer Polytechnic Institute have only made milligram doses of the product -- a commonly used blood thinner -- but they are already working on ways to expand production to kilograms.

Currently, heparin is derived from pigs' intestines.

Linhardt presented his work, which follows years of stitching together minuscule carbohydrates molecules, at the national conference of the American Chemical Society at the weekend.

"Ultimately, drug companies are going to need to produce tons of this drug to keep up with global demand," Linhardt said.

"Such levels of productions are further down the road. We think that in five years, it is very possible that this drug could reach human clinical trials."

Heparin, an injected drug, is widely used in hospitals to reduce the risk of blood clots after surgery. But the medicine has been dogged by controversy following a series of contamination problems.

In the United States, tainted heparin from China was used by at least 81 patients who died soon afterwards. They suffered serious allergic reactions, with plummeting blood pressure, swelling of the larynx and other severe symptoms.

Baxter International (BAX.N) recalled supplies of its heparin products following the incident.

Much smaller-scale contamination problems were also reported with Sanofi-Aventis's (SASY.PA) top-selling heparin medicine Lovenox in several markets.

Linhardt said the episode showed today's manufacturing methods were simply unsafe.

"Unlike the current heparin that is harvested from possibly disease-carrying animals in often very poor conditions, our fully synthetic heparin will be created in a pharmaceutical manufacturing environment," he said in a statement. (Reporting by Ben Hirschler; Editing by Toby Chopra)