Development and validation of simple RP-HPLC-PDA analytical protocol for zileuton assisted with Design of Experiments for robustness determination

A simple, rapid, sensitive, robust, stability-indicating RP-HPLC-PDA analytical protocol was developed and validated for the analysis of zileuton racemate in bulk and in tablet formulation. Development of method and resolution of degradation products from forced; hydrolytic (acidic, basic, neutral), oxidative, photolytic (acidic, basic, neutral, solid state) and thermal (dry heat) degradation was achieved on a LC- GC Qualisil BDS C18 column (250 mm x 4.6 mm x 5 mu m) by isocratic mode at ambient temperature, employing a mobile phase methanol and (0.2 A, v/v) orthophosphoric acid in ratio of (80:20, v/v) at a flow rate of 1.0 mL min(-1) and detection at 260 nm. 'Design of Experiments' (DOE) employing 'Central Composite Design' (CCD) and 'Response Surface Methodology' (RSM) were applied as an advancement to traditional 'One Variable at Time' (OVAT) approach to evaluate the effects of variations in selected factors (methanol content, flow rate, concentration of orthophosphoric acid) as graphical interpretation for robustness and statistical interpretation was achieved with Multiple Linear Regression (MLR) and ANOVA. The method succeeded over the validation parameters: linearity, precision, accuracy, limit of detection and limit of quantitation, and robustness. The method was applied effectively for analysis of in-house zileuton tablets. (C) 2014 King Saud University. Production and hosting by Elsevier B.V.