Chinese chemists have joined animal rights groups in search of substitutes for bear bile, which is believed to help cure ailments such as eye and liver problems.

"Research and development of substitute ingredients are essential in protecting animal welfare and boosting technological advancements," said Prof. Gao Yimin, an expert on traditional Chinese medicine at the Beijing-based Capital Medical University.

At a forum sponsored by Animals Asia Foundation (AAF), a non-government organization engaged in animal welfare, in Beijing Tuesday, Prof. Gao said China's success in developing artificial musk, a substance obtained from the gland of male musk deer, could be copied to save bears from the torture of bile extraction.

China has 68 registered bear farms where more than 10,000 black bears are kept for bile extraction. These farms produce about 30 tonnes of bear bile powder in total each year.

In Chengdu, capital of southwest China's Sichuan Province, bear bile powder can sell for as high as 4,000 yuan (597 U.S. dollars) a kilogram. Some high-end alcohol and shampoo products list bear bile as an ingredient.

According to a survey by AAF, about 190 drugs containing bear bile are sold on the Chinese market, most of which have similar functions, treating sore throats and hemorrhoids.

Bile extraction, however, was an extremely cruel process that often caused liver cancer or organ failure and eventually killed many bears, said AAF veterinary director Heather Bacon.

Of the 345 bears AAF had rescued from farms nationwide, 100 percent suffered gallbladder inflammation, said Bacon.

To prevent infection and to keep the animals alive for further bile extraction, an excessive amount of antibiotics were often used, said Cai Chengyuan, a researcher with the Chinese Academy of Agricultural Sciences.

Tests by the AAF had found traces of antibiotics in samples of bear bile, which could prove harmful to people who consumed the products, said Cai.

A herbal expectorant for injection, produced by a Shanghai pharmaceutical firm that consumes at least half of the country's bear-bile powder, has been suspected of causing serious allergies, including shock, high fever, as well as heart and kidney failure, he said.

"At least one leading Shanghai hospital has banned use of the injection," he said.

In 2001, China's Ministry of Health stopped approving healthcare products using bear-bile powder in an effort to preserve wildlife resources and ensure food and drug safety.

Authorities have also encouraged research of substitute ingredients for bear bile.

At least 50 herbal and synthetic substitutes have been proved to have the same medical effect, but are much cheaper than bear bile, said Prof. Jiang Qi, a leading herbalist in Shenyang, capital of northeastern Liaoning Province.

Earlier this year, four popular Chinese pharmacy chains joined the AAF campaign by refusing to sell bear-bile products.

"Yet it takes time for all the pharmacies to stop using bear bile," said Prof. Jiang.

For more than 3,000 years, bears have been hunted in Asian countries for their gallbladders and the valuable bile within. China banned bear hunting in the 1980s after rampant hunting greatly reduced the bear population.

However, wild bears were then caught and farmed for their bile.

By the end of 2009, bear farming was still legal in 13 of the Chinese mainland's 31 provinces, municipalities and autonomous regions.

Chinese authorities have agreed to issue no new licenses and work towards ending bear farming across the nation.