Determination of atovaquone in tablets by differential pulse polarography

A differential pulse polarographic method is presented for the determination of atovaquone in its pharmaceutical formulations. The polarographic behaviour of atovaquone was examined in various buffer systems over the pH range 3.0-10.0. In Britton Robinson buffer/methanol solution (1:1; v/v; pH 8.5) the differential pulse polarograms exhibited reproducible peaks at Ep - 0.43 V vs. silver/silver chloride/potassium chloride (3M). Under these conditions, strict linearity between atovaquone concentration and peak height was observed in the 2.7 x 10(-6)-3.5 x 10(-5) M concentration range. The detection limit was calculated to be 0.41 mug/ml. The polarographic method was applied to the determination of the content of atovaquone in various pharmaceutical preparations. For the polarographic analysis of atovaquone in Wellvone((R)) and Malarone((R)) tablets no separation step was necessary. In order to evaluate the concentration of atovaquone, the standard addition method was applied. The analysis of Wellvone((R)) tablets led to a mean value of 250.4 mg with a relative standard deviation (S-rel) of 2.1% and of Malarone((R)) tablets 252.3 mg with a S-rel of +/-2.4%.