科学与发展网络(SciDev.Net)

Genuine artesunate tablets

WHO/TDR/Crump

[BEIJING] The results of analyses of fake antimalarials which led to the arrests of counterfeit drug producers in China have been published.

An international consortium of scientists, known as 'Operation Jupiter', conducted physical, chemical and biological analyses on 391 samples of the antimalarial drug artesunate from South-East Asian countries such as Cambodia, Laos, Myanmar and Vietnam.

They published their findings in PLoS Medicine this month (12 February).

Half of the samples turned out to be fake. Most of the fakes contained no trace of artesunate, but some had small amounts of the compound at the surface of the tablet to pass inspection by local drug regulators.

Some counterfeits also contained potentially toxic chemicals, such as safrole, a carcinogen used in the manufacture of the illegal drug ecstasy.

The scientists warn that the wrong ingredients could cause inexplicable side effects, such as bone marrow failure, and that using small amounts of artesunate is likely to promote resistance to the drug.

The chemical analyses also revealed that some of the chemical ingredients in the fakes might have been produced in southern China. This was supported by testing for plant spores and pollen — contained in the same packets as the fake drugs— which were found to come from southern China and northern Vietnam.

The researchers submitted their evidence to the Chinese authorities in 2006. Arrests were made in the southern Chinese provinces of Yunnan and Guangxi later that year.

Paul Newton, of the Wellcome Trust-University of Oxford South-east Asian Tropical Medicine Research Programme and lead author of the study, says more scientific information like this would allow the police to focus their criminal investigations and add further court-admissible evidence.

Similar investigations would also help deter counterfeit drug makers, reducing the losses of genuine antimalarial drug producers, says Liu Zhanglin, director of the traditional Chinese medicine department at the China Chamber of Commerce for Import and Export of Medicines and Health Products.

However, Li Ying, a senior scientist of the Shanghai Institute of Materia Medica of the Chinese Academy of Sciences and one of the first scientists to start developing artemisinin, says the research is largely based on sophisticated analyses using costly equipment.

"If local drug regulators in developing countries are not equipped with easily portable, operable and low-cost analysis equipment, it is still very difficult for them to effectively and efficiently prevent fake drugs against malaria," Li told SciDev.Net.

Link to full paper in PLoS Medicine

Reference: PLoS Medicine e32 doi:10.1371/journal.pmed.0050032