Eco-friendly chiral HPLC method for determination of alfuzosin enantiomers and solifenacin in their newly pharmaceutical combination: Method optimization via central composite design

Abstract

The high abundance and advantages of polysaccharides make them among the most widely used chiral stationary phases in liquid chromatography. However, extended analysis time and consumption of toxic organic solvents, associated with traditional columns, remain the main stumbling blocks of such methods’ sustainability. A new green chiral HPLC-separation, with just 0.45 mL ethanol in mobile phase per run utilizing a 50-mm column as a stationary phase, achieves a significant determination of alfuzosin (ALF) enantiomers along with solifenacin (SOL) simultaneously. Enantioseparation of ALF was firstly evaluated in the reversed-phase mode using five polysaccharide-based Lux columns (Amylose 2 and Cellulose 1–4), highlighting Lux Cellulose 2 to reach the best enantioselectivity. Central composite design with Derringer's desirability function was then adopted to optimize the chromatographic conditions for an acceptable resolution. A mobile phase composed of ethanol and phosphate buffer, pH 4, (30:70, v/v) at a rate of 0.5 mL/min with UV-detection at 215 nm, exhibits good separation of ALF-enantiomers from SOL with resolution values of 1.45 and 2.64, respectively. The method’s greenness profile has been assessed and compared with that of mostly reported ones via the newest comprehensive analytical method greenness score (AMGS) calculator. The proposed method is considered a straightforward approach towards safer, more economic, eco-friendly and comparatively favorable for the cited drugs’ quantification in their formulation.