The initial pharmaceutical development of an artesunate/amodiaquine oral formulation for the treatment of malaria: a public-private partnership.

BACKGROUND: Artemisinin-based combination therapy is currently recommended worldwide for the treatment of uncomplicated malaria. Fixed-dose combinations are preferred as they favour compliance. This paper reports on the initial phases of the pharmaceutical development of an artesunate-amodiaquine (ASAQ) bilayer co-formulation tablet, undertaken following pre-formulation studies by a network of scientists and industrials from institutions of both industrialized and low income countries. METHODS: Pharmaceutical development was performed by a research laboratory at the University Bordeaux Segalen, School of Pharmacy, for feasibility and early stability studies of various drug formulations, further transferred to a company specialized in pharmaceutical development, and then provided to another company for clinical batch manufacturing. The work was conducted by a regional public-private not-for-profit network (TropiVal) within a larger Public Private partnership (the FACT project), set up by WHO/TDR, Médecins Sans Frontières and the Drugs for Neglected Disease initiative (DNDi). RESULTS: The main pharmaceutical goal was to combine in a solid oral form two incompatible active principles while preventing artesunate degradation under tropical conditions. Several options were attempted and failed to provide satisfactory stability results: incorporating artesunate in the external phase of the tablets, adding a pH regulator, alcoholic wet granulation, dry granulation, addition of an hydrophobic agent, tablet manufacturing in controlled conditions. However, long-term stability could be achieved, in experimental batches under GMP conditions, by physical separation of artesunate and amodiaquine in a bilayer co-formulation tablet in alu-alu blisters. Conduction of the workplan was monitored by DNDi. CONCLUSIONS: Collaborations between research and industrial groups greatly accelerated the process of development of the bi-layered ASAQ tablet. Lack of public funding was the main obstacle hampering the development process, and no intellectual property right was claimed. This approach resulted in a rapid technology transfer to the drug company Sanofi-Aventis, finalizing the process of development, registration and WHO pre-qualification of the fixed-dose co-formulation together with DNDi. The bi-layered tablet is made available under the names of Coarsucam® and Artesunate amodiaquine Winthrop®, Sanofi-Aventis. The issue related to the difficulty of public institutions to valorise their participation in such initiative by lack of priority and funding of applied research is discussed.

Fixed artesunate-amodiaquine combined pre-formulation study for the treatment of malaria.

Artemisinin-based combination therapies, including artesunate (AS)+amodiaquine (AQ), are the currently recommended first-line treatment of uncomplicated falciparum malaria. Fixed-dose co-formulations offer logistic and adherence advantages. This paper reports the initial research phase of the pre-development process of an AS-AQ formulation, further developed by the Drug for Neglected Diseases Initiative (DNDi). Results demonstrate that AS and AQ are not compatible, and AS degradation is related to three main parameters: water content (>1%), elevated temperature (80 degrees C in dry condition) and possibly the 4-aminoquinoline moiety. Furthermore, AS and AQ incompatibility led to AS degradation and pharmaco-technical changes in classical wet granulation tablets. Both active principles are stable as dry powders. These investigations led to further development of various co-formulations, including the bilayer tablet currently on the market.

Fixed artesunate-amodiaquine combined pre-formulation study for the treatment of malaria.

Artemisinin-based combination therapies, including artesunate (AS) + amodiaquine (AQ), are the currently recommended first-line treatment of uncomplicated falciparum malaria. Fixed-dose co-formulations offer logistic and adherence advantages. This paper reports the initial research phase of the pre-development process of an AS-AQ formulation, further developed by the Drug for Neglected Diseases Initiative (DNDi). Results demonstrate that AS and AQ are not compatible, and AS degradation is related to three main parameters: water content (>1%), elevated temperature (80 degrees C in dry condition) and possibly the 4-aminoquinoline moiety. Furthermore, AS and AQ incompatibility led to AS degradation and pharmaco-technical changes in classical wet granulation tablets. Both active principles are stable as dry powders. These investigations led to further development of various co-formulations, including the bilayer tablet currently on the market.