Original Articles
Divya N. Shetty, B. Narayana*
Abstract
Two new methods are proposed for the determination of dihydroartemisinin (DHA), artemisinin (ART), and artesunate (ARTS) in pure form and in pharmaceutical formulations. Method A is based on the formation of blue colored chromogen when the drugs react with Folin-Ciocalteu’s (F-C) phenol reagent in alkaline medium. The colored species have absorption maxima at 722, 721 & 741 nm and second method uses bromate-bromide mixture and crystal violet (CV) as reagents, the absorbances of which could be measured at 596 nm. First method obeys Beer’s law in the concentration range of 10.00– 120.00, 10.00-80.00 and 10.00-80.00 μg mL-1 for FC-DHA, FCART and FC-ARTS systems respectively and second method obeys Beer’s law in the concentration range of 2.00- 20.00, 2.00-22.00 & 2.00-30.00 μg mL-1 for DHA, ART, & ARTS respectively . The apparent molar absorptivities for the first method are calculated to be 0.11 x 104, 0.23 x 104 and 0.1 x 104 lmol-1cm-1 and for the second method 5.92 x 104, 3.98 x 104 & 1.37 x 105 for DHA, ART & ARTS respectively. The proposed methods are successfully applied to the determination of ARTS in pharmaceutical formulations.