Development and validation of a thin layer chromatographic method for the determination of artesunate and amodiaquine in tablet formulations
Artemisinin-based combination therapies (ACTs) are recommended for the treatment of uncomplicated falciparum malaria. Artemisinin derivatives are potent, rapidly acting antimalarias that reduce gametocyte carriage and patient infectivity; the sustained use of artesunate – amodiaquine reduced falciparum malaria transmission and progression of drug resistance. High efficacy of artemisinin-based combinations (artesunate plus amodiaquine) was observed in areas where malaria is endemic. This paper describes a routine, simple, precise, economical and reproducible thin layer chromatographic technique for the detection of artesunate and amodiaquine in tablet dosage form. Chromatographic separation was performed on glass silica gel plates (20 × 20 cm), paraffin – n-hexane (2:3 v/v) and ethylacetate – toluene (2.5:47.5 V/V) as mobile phases. Artesunate exhibited a detection limit of 0.001 mg/ml, while that of amodiaquine was 0.05 mg/ml. The two drugs were satisfactorily resolved with mean Rf values of 0.04 ± 0.03 and 0.06 ± 0.07 for artesunate and amodiaquine, respectively. The accuracy and reliability of the method was assessed by evaluation of linearity (0.001 – 6.0 and 0.05 – 6.0 mg/ml for artesunate and amodiaquine), precision (intraday RSD 10.68 – 25.78% and interday RSD 10.68 – 20.17 for artesunate, and intraday RSD 8.25 – 37.26% and inter day RSD 8.25 – 19.74% for amodiaquine) and specificity, in accordance with International Conference for Harmonization (ICH) guidelines. The method developed can be used for the analysis of ten or more formulation on a single plate and is a rapid and cost-effective quality-control tool for routine analysis of artesunate and amodiaquine as the parent drug and in tablet formulations.
Key words: Artemisin based combination therapy (ACT), malaria, falciparum, artesunate, amodiaquine.