Successfully Combating Fake Drugs in Africa

Roger Bate | 15 Jun 2010
American.com
A new study finds public- and private-sector efforts having a positive effect on poor quality medicines in two West African cities. Substandard and counterfeit drugs can be lethal to patients and accelerate drug resistance across at-risk populations. This is a major problem for diseases like malaria with few high-quality treatments available. Some African governments, notably Nigeria and Ghana, have responded to this challenge, often with help from donors, and have deployed an array of technologies to assist them. Both countries have uncovered fake drugs in their markets: In Nigeria, after finding myriad fakes, the authorities banned imports from many small and mid-sized producers in India and China. Last year, one of the drug quality monitoring sites in Ghana, supported by the U.S. government, was the first location anywhere to discover a counterfeit version of the leading artemisinin-based combination therapy (ACT), Coartem (artemether-lumefantrine). But while some dangerous perpetrators are now in jail, the question is whether these efforts have improved quality for the wider population?

In 2007, our research team sampled anti-malarial drugs in six African cities and found that roughly a third of the medicines failed at least one quality-control test (see here). The headline failure rates for samples found in the cities of Accra and Lagos were 35 percent and 32 percent respectively. Samples were collected again in February 2010 and, as published today in the Malaria Journal, failure rates for the same drug types fell to 19 percent and 10 percent respectively (see here). This is a notable improvement, especially in Lagos, and although problems remain, efforts to combat drug counterfeiters and those making substandard products are working.

But the details of the testing results might point to other potential problems for authorities.

The drugs were tested using the Global Pharma Health Fund Minilab, which included thin layer chromatography assay for active pharmaceutical ingredient (API), disintegration, and visual inspection. For comparison, a handheld Raman spectrometer, the same type used by the Nigerian authorities, was also used as a fourth field assessment method. All methods revealed a trend in improved quality over time, with the greatest improvement observed with the API assay.

There seems to be two plausible explanations for this disparity:

First, the spectrometer provides a spectrum, like a fingerprint, for the entire pill, including API, plus excipients (fillers, dyes, and coatings). A method or model spectrum has to be developed for each brand to use as a comparison, and, due to the sensitivity of the spectra, the model must be developed from several samples to allow for variation among drugs manufactured at different facilities.

Some of the sample sizes in our study may not have been sufficient to allow for product variation, which may explain why more samples "failed" with the Raman spectrometer than with the Minilab tests.

Another possible explanation is that the spectrometry results are relatively accurate, but the Minilab API assay is providing too many false positives. There are reasons to believe this could be the case. First, counterfeiters have been able to adapt to changes in packaging and content in the past. In Southeast Asia, 16 different holograms were copied by counterfeiters to pass off their anti-malarial drugs . And prior to the deployment of Minilabs, counterfeiters, some caught on camera by the BBC for the documentary Bad Medicine, added a small amount of API to products. They did so in order to pass rapid dye tests, which had been deployed by anti-counterfeit agencies to find fakes. So the notion that counterfeiters would adapt again and add much more API, whilst still not ensuring a good quality product, is certainly plausible.

Some fake drug investigators in India and China believe that at least some counterfeiters are indeed making a wider array of fakes, including adding far more API for certain markets. Of course, they make less money this way, but avoiding detection while accepting lower profits may be an efficient trade-off from their perspective.

While the Minilab protocol does encourage users to have suspicious samples sent to a laboratory for full compendial analysis, this doesn't address apparently well-packaged fakes that pass API assay. Perhaps authorities should randomly test samples of drugs that pass the Minilab API assay to determine whether devious counterfeiters are undermining the assay; this may be too expensive, however, given the cost of a full laboratory analysis.

Alternatively, the Nigerian authorities could establish robust model spectra for the handheld spectrometers they already own, which are far faster and cheaper to use to detect fake products in the field. In addition, a baseline comparison with large sample sizes would be useful, and may resolve the question of whether the results seen in our study were based on flawed spectral methods, or counterfeiters' adaptations.

In the meantime, we shouldn't lose sight of the bigger picture, which is that Nigerian and Ghanaian authorities, as well as private pharmaceutical companies, at least in the cities of Lagos and Accra, are doing a good job of lowering the rate of fake drugs. And what they and their donors are doing should be better understood and copied in other areas.

http://blog.american.com/?page_id=15321