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

Abstract

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 the
reaction of the reactive methylene centres generated in situ from the acid decomposition of the
artemisinin derivatives with p-dimethylaminobenzaldehyde (DMAB). DMAB was reduced to the
purple-coloured alcohol and this was quantitatively used to estimate the concentrations of the
artemisinin derivatives. The new procedure was carried out at 60oC in less than 30 minutes with
excellent 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.