Implementation of Analytical Quality-by-Design for Developing a Robust HPLC Method for Quantitative Estimation of Voriconazole: Application in Drug Formulations

Abstract

The current studies endeavour to develop and validate a simple, sensitive and robust reversed- phase (RP) high-performance liquid chromatography (HPLC) methodology for quantitative estimation of voriconazole (VRC), following systematic principles of Analytical Quality-by-Design (AQbD). A comprehensive risk assessment plan, followed by factor screening studies employing Taguchi design, was executed to select “vital few” critical method parameters, influencing critical analytical attributes. Subsequently, response surface optimisation studies were conducted on the identified critical method parameters, viz., mobile phase ratio and flow rate, with chosen critical analytical attributes, viz., peak area, theoretical plate count, retention time and peak tailing, employing a Central Composite Design. The design space, demarcating the optimal method operating conditions, was identified using graphical optimisation and subsequently validated employing Monte Carlo simulations. The optimal solution consisted of acetonitrile and acetic acid solution (0.05 %, pH 4) as mobile phase (50:50 v/v), flow rate of 1 mL/ min with a detection wavelength of 256 nm, exhibiting linearity between 0.1 and 50 μg/mL in methanol and Hanks balanced salt solution. Validation studies confirmed precision (97.78-103.42 %), accuracy (98.99-102.34 %), and suitability of the developed analytical method for effective quantification of VRC with high sensitivity (LOD: 0.031 μg/mL; LOQ: 0.093 μg/mL). The validated analytical technique was successfully ratified for quantification of VRC in drug nanoformulations too. In a nutshell, the application of AQbD and Monte Carlo simulations aided in developing a robust analytical method for the estimation of VRC per se as well as in drug nanoformulations.