Determination of the antimalaria drug artemether in pharmaceutical preparations by differential pulse polarography

A differential pulse polarographic method has been developed for the determination of artemether in its pharmaceutical formulations. The polarographic behaviour of artemether was examined in various buffer systems over the pH range 3.0-10.0. In phosphate buffer pH 5.5/methanol solution (7:3, v/v) the differential pulse polarograms displayed reproducible peaks at Ep-0.01 V versus Ag/AgCl. Under these conditions strict linearity between artemether concentration and peak height was observed in 3.4x10(-7)-3.0x10(-5)mol/L concentration range (R=0.9998). The detection limit was calculated to be 32 ng/mL. The polarographic method was applied to the determination of the content of artemether in tablets and capsules by using the standard addition method. The analysis of tablets containing 20mg artemether showed a mean value of 19.73 mg with a relative standard deviation (R.S.D.) of +/-1.01%. A content of 39.74 mg artemether was found in 40 mg capsules with a relative standard deviation of +/-0.53%. The polarographic method is characterised to be cheap, precise and not time-consuming and can therefore be used for routine analysis of artemether in its pharmaceutical preparations.