Reverse Phase-High-Performance Liquid Chromatography (RP-HPLC) Method Development and Validation Using Analytical Quality-by-Design Approach for Determination of Isoliquiritigenin in Bulk and Biological Sample.

The primary objective of the present investigation is to develop and validate a simple, robust, and cost-effective isocratic reverse phase-high-performance liquid chromatography (RP-HPLC) method for determining isoliquiritigenin (ISL) in both bulk and biological samples using an analytical quality-by-design (AQbD) approach. The central composite design was employed for method optimization using Design Expert® software, by taking mobile phase ratio and flow rate as independent variables and peak area, retention time, tailing factor, and theoretical plates as dependent variables. The design suggested the use of a mobile phase consisting of acetonitrile:0.