Researchers are developing two prototype tests to detect fake anti-malarial tablets in just five seconds. Conventional methods take more than two hours, says a report on the award-winning Science and Development Network’s website, SciDev.Net.
The new techniques, developed by Facundo Fernandez of the Georgia Institute of Technology in the United States and colleagues, will be published this summer in the journal ChemMedChem. They can be used to detect tablets that contain less than the recommended dose of artesunate — believed to be the most effective anti-malarial drug — and the presence of other less effective or harmful active ingredients.
Fernandez’s team has improved two existing methods known as “desorption electrospray ionisation” (Desi), developed by Purdue University in the United States, and “direct analysis in real time” (Dart), developed by a Japanese company.
The first, Desi, is not sufficiently sensitive to detect artesunate. Fernandez’s team added a compound to stabilise the substance, which made it easier to detect. In addition, the team is combining the latter technology, Dart, which accelerates screening, with instruments already used to detect counterfeit drugs.
One such instrument is a mass spectrometer, but this is too bulky and expensive to use outside laboratories. The team plans to combine direct analysis in real time with a similar instrument used in airports to detect explosives that will be adapted to screen anti-malarial drugs.
The researchers used the techniques to screen artesunate tablets from Laos, Myanmar and Thailand. They found tablets containing waste powders left over from the manufacture of other pharmaceuticals, an analgesic suspected of causing serious bone-marrow disorders and anti-malarials that are ineffective in South-East Asia.
They also found tablets containing 10mg of artesunate instead of the 50mg present in the genuine product. Low doses of artesunate are dangerous in the long term as they could help resistant strains of the malaria parasite emerge.
In another article published this week by the open-source Public Library of Science online peer-reviewed journal Medicine, a team of researchers from Asia, Africa and Europe says that up to half of the artesunate pills in South-East Asia could contain no active ingredient at all.
The research done by 21 scientists has the hard-hitting title Manslaughter by Fake Artesunate in Asia: Will Africa Be Next?. Authors include Dr Ambrose Talisuna of the East African Network for Monitoring Antimalarial Treatment and ministry of health in Uganda, Dr Grace Malenga from the Malaria Alert Centre in Blantyre in Malawi and Dr Kalifa Bojang from the Medical Research Council laboratories in Banjul in The Gambia.
Between 38% and 52% of the tablets they sampled were made of starch, chalk and a variety of unconventional active ingredients. They say counterfeit drugs have led to an unnecessary loss of life for profit and a loss of confidence in artesunate, and have given rise to false reports of resistance to the drug.
In 2004, 34 countries in Africa adopted artemisinin-based therapies as their first line of treatment against malaria. The spread of counterfeits is exacerbated by the high cost and short supply of artemisinin.
A report in the respected science journal Nature earlier this year, available online at SciDev.Net, warned that an increasing number of people in South-East Asia are lured into buying fake medicines, not knowing that these cheaper “lookalike” drugs often do not work.
Investigations have shown that drug counterfeiting — the making of drugs that either have no active ingredients or have the wrong ones — is rising, but the number of deaths it causes is still largely unknown. Scientists and health officials are working to raise awareness among local doctors and patients about the problem.
Experts discussed possible solutions in Paris, France, at the Second Global Forum on Pharmaceutical Anticounterfeiting this year.
Nature‘s chief news and features editor, Peter Aldhous, says that the lack of official response, high costs of drug testing, shortage of qualified staff, unlicensed outlets and corruption are all factors that encourage drug counterfeiting. He adds that if the problem is to be tackled at its source, efforts should start in China where most of the drugs are made.
But there is hope. A “minilab” project, for instance, involving a portable kit for drug testing, offers a cheap method of identifying counterfeits. — SciDev.Net