A New HPTLC Method for Analysis of Artemisinin Derivatives (Artemether and Lumefantrine) in Bulk Drug and Liposomal Formulation: Stress Degradation Study
Purpose: A stability indicating high performance thin layer chromatography (HPTLC) method has been established and validated for analysis of two anti-malarial drugs, ART and LUM in bulk drug as well as nanoliposomal formulation. Materials and Methods: Study was performed on pre-coated silica gel HPTLC plates using toluene:ethyl acetate:amonia (2:6.5:0.5 v/v/v) as the mobile phase. Densitometric analysis was carried out in the reflectance mode at 269nm for LUM and 519nm for ART. The method is specific for analyte constituents examined and characterized by high sensitivity. Results: The correlation coefficients of calibration curves were found to be 0.997 and 0.998 in the concentration range of 20-120 and 100- 300 ng spot-1 for ART and LUM, respectively. The method had an accuracy of 100.5 % for ART and 100.4% for LUM. Conclusion: The method had the potential to determine these drugs simultaneously from bulk drug as well as nanoliposomal formulation without any interference of the excipients. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating one. Moreover, the proposed HPTLC method was utilized to investigate the kinetics of acid and base degradation process. Arrhenius plot was constructed and activation energy was calculated.