Stability Indicating HPTLC Method for Estimation of Modafinil in the Bulk and Tablet Formulation

A simple, selective, precise and stability-indicating high-performance thin layer chromatographic method for analysis of Modafinil, both as the bulk drug and in a tablet formulation has been developed and validated. Aluminum foil TLC plates precoated with silica gel 60F 254 were used as stationary phase ethyl acetate, acetone and methanol in the volume ratio of (7:2:1 v/v) respectively as mobile phase. A compact band (Rf 0.42±0.02) was obtained for modafinil. Densitometric analysis was performed in absorbance mode at 232 nm. Linear regression analysis revealed a good linear relationship (r=0.9995) between peak area and concentration in the range of 80-320 ng /spot. The method was validated for precision, recovery, and robustness. The limits of detection and quantitation were 15 and 50 ng/spot, respectively. Modafinil was subjected to acid and alkaline hydrolysis, oxidation, photochemical and thermal degradation and underwent degradation under all these conditions. Statistical analysis proved the method enables repeatable, selective, and accurate analysis of the drug. It can be used for identification and quantitative analysis of Modafinil in the bulk drug and in tablet formulations.