Analytical Quality Risk Assessment and Design of Experiments to Green HPTLC Method for Simultaneous Estimation of Sildenafil Citrate and Dapoxetine Hydrochloride.

A green and robust high-performance thin-layer chromatographic method has been developed for the simultaneous estimation of sildenafil citrate and dapoxetine hydrochloride. A fractional factorial design was applied for analytical quality risk assessment of potential analytical risk factors. The identified critical analytical risk factors were optimized using the design of experiment-based response surface analysis by full factorial design. The analytical design space was navigated for the optimization of the method and the control strategy was framed for low-risk life-cycle management of the chromatographic method. The chromatographic analysis of sildenafil and dapoxetine was carried out on a TLC plate coated with silica gel G60 F254 using n-butanol:ethyl acetate:ethanol (8.0 + 2.0 + 0.5, v/v) as mobile phase. The chromatographic peaks of sildenafil and dapoxetine were found to be at Rf 0.29 and 0.69, respectively. The method was found to be accurate, precise, robust, specific and sensitive. The fixed-dose combinations of sildenafil and dapoxetine were assayed and results were found in compliance with their labeled claim. The present method was developed using safe and eco-friendly organic solvents for the safety of analysts and the protection of the environment. The greenness profiles of developed and reported methods were evaluated using the NEMI scale and AGREE software.