Original Articles
Attih EE, Johnson EC, Ambe DA,
Abstract
Artesunate (ART) is a frontline drug for the treatment of malaria, mostly in combination with other antimalarial, such as amodiaquin. There are reported cases of widespread manufacture of ART and other artemisininderivative derivatives in South-East Asia and sub-Saharan Africa. If this trend is not checked there is likely going to be public health crises as this may likely lead to the emergence of multidrug resistant plasmodium parasites. Bearing this in mind three simple methods are developed based on the use of chloramine T as the oxidometric reagent. In method 1 choramine T is titrated directly with the drug while in the second titrimetric and the spectrophotometric methods known excess of chloramine T is determined after the redox reaction with increasing amount of ART. The three methods are stoichiometricand qualitative. In the trimetric method A (direct) and the indirect iodometric method B, the amount of the ART determined was proportional to the concentration of the chloramine T. in the spectrophotometric method Beer’s law was obeyed in the range of 0.5-50 µg as shown in the calibration graph generated. The correlation coefficient of 0.9998 was obtained based on least square method. The molar absorptivity and Sandell sensitivity were 2.6 × 104 L/mol/cmand 0.0168 µg/ml respectively. The limit of detection and quantification were determined as per current ICH guidelines and found to be 0.0756 – 0.36 respectively. The methods were statistically compared with an official method via student T test and varianceratio test (F test) with calculated values lower than the tabulated values in all cases showing good accuracy and precision. The proposed methods were then used to determine locally purchased ART tablets in Uyo, Nigeria. The workability and accuracy of the methods were further confirmed byrecoverystudies via standard addition method. The results show that pharmaceutical excipients had no effect on the methods.