Derivatization of Artesunate and Dihydroartemisinin for Colorimetric Analysis using p-dimethylaminobenzaldehyde

We set out to develop an alternative simple, accurate and precise method for the determination of artesunate and dihydroartemisinin in bulk samples and dosage forms. The method involves thereaction of the reactive methylene centres generated in situ from the acid decomposition of the artemisinin derivatives with p-dimethylaminobenzaldehyde (DMAB). DMAB was reduced to thepurple-coloured alcohol and this was quantitatively used to estimate the concentrations of the artemisinin derivatives. The new procedure was carried out at 60°C in less than 30 minutes withexcellent calibration data. The method was accurate and precise and was found equivalent to the International Pharmacopoeia’s method for the assay of these drugs. The method could find application as an alternative in-process and after manufacture method for the quality control of artesunate and dihydroartemisinin.