Abstract
TLC densitometric method for simple and sensitive stability assessment of modafinil has been developed. The objective was to provide a rapid, precise, robust, and reproducible technique for the analysis of modafinil. The method was validated for bulk drug and tablet formulations. It could be used to separate the drug from its degradation products. The procedure employed TLC aluminum plates precoated with 60F-254 silica gel as the stationary phase. The solvent system consisted of toluene-chloroform-methanol (1: 1 0.5, v/v/v) mixture. It provided well-resolved compact spots for modafinil (R-f value 0.46 +/- 0.01) and allowed for separation of the excipients and degradation products. Densitometric scanning interegation was performed at the wavelength of 220 nm. Calibration plot was linear r(2) = 0.999) in the analyte concentration range 100-5000 ng per spot. The method was validated with respect to linearity, accuracy recovery, precision, ruggedness. and specificity. The limit of detection and quantification were 20.54 ng per spot and 62.26 ng per spot, respectively. The determined drug content was within the +/-5% range of the labeled content. The drug was analyzed tinder different stress conditions in order to Study its degradation in the presence of acid, base, and peroxide.