Optimisation of the reversed phase liquid chromatographic separation of atovaquone, proguanil and related substances.

The optimisation of the separation of the antimalarial drugs, proguanil and atovaquone and six related compounds was obtained by two independent optimisation steps; the optimisation of the mobile phase composition and the optimisation of the pH. This was done using window selection diagrams (WSD) and a mixture design. The optimal conditions allow the identification of the six related compounds down to 0.1%.