E-DRUG: Instability of medicines under tropical circumstances
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Dear Dr. Fundafunda,
Your recent letter in e-drug (ref Global storage conditions for medicines (4)) is most important to me. The pharmaceutical discipline has been hammering on the necessity of quality of the drugs and of course, this also implies their stability. In your letter you are defending this principle arguing that in certain tropical conditions, drugs which cannot survive should not be distributed for sales. To my opinion, violation of this basic rule of stability should not be permitted, and under no circumstances. In this context I would like to draw your attention to the instability of some recently developed DHA-based antimalarial combination therapies that can also be found on the African markets. You may recall that in 2010, I published a warning article in Malaria Journal "The pharmaceutical death ride of Dihydroartemisinin" (Malaria Journal, 2010, 9:212, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2916014/pdf/1475-2875-9-212.pdf). The reason was that at the time of publication, none of the DHA-based preparations available on the African market did comply with recommended quality guidelines following exposure to zone III and IV conditions. In fact in these "medicaments" breakdown of DHA was sometimes exceeding 50%. Apart from the risks created by unknown breakdown products present in these formulations, such reduction in content of the active ingredient can be very critical and damaging as the patients no longer get the appropriate therapeutic dose of the drug. To me this is the equivalent of bringing false or counterfeit drugs to the market.
At the light of this initial study, I feel most concerned about the newly-developed combination DHA-Piperaquine (Eurartesim) a joint development between Sigma Tau in Italy and Malaria Medicine Venture (MMV)), which is now one of the drugs currently recommended by WHO's program for the treatment of malaria. To my opinion this drug should not be on the list of recommended treatments if it is not stable at climatic zone III and IV. In a recent assessment report from the European regulatory commission (EMA) on this drug, the commission is very clear that the stability data presented by the sponsor cannot be extrapolated to zone III and IV [it is referred to page 17 in the report, the moderator could not locate the report]. Based on this assessment should one understand that the ACT combination DHA-PPQ does not pass stability at climatic zone III and IV and therefore should not be promoted in Africa and in other places with high temperatures and humidity, or is it simply that the stability data were not presented? Has the data been presented to WHO? If yes, is this data also available to the public? I think the scientific and pharmaceutical community has the right to know where this product stands in terms of stability at tropical conditions.
Sincerely yours,
Dr. F.H. Jansen, Ph.D.
ACT-ion Afrique
Brussels
Belgium