Abstract
Supercritical fluid chromatography employing chiral stationary phases is a popular separation technique to perform enantioselective separations. The main advantages of supercritical fluid chromatography are low analysis time, low consumption of organic modifiers, and therefore lower costs and higher environmental friendliness.
A novel method for the separation of chlorthalidone enantiomers, widely used diuretic drug, is reported that clearly demonstrates the advantages of supercritical fluid chromatography. The effects of the amount and type of organic modifiers, temperature, and back pressure on enantioselectivity and resolution of the enantiomers were evaluated.
The baseline separation was achieved in less than 2.5 min in the optimized system composed of Chiralpak AD column, mobile phase CO2/ MeOH 50/50 (v/v), temperature 40C, a flow rate of 4.0mL/min, and 120 bar back pressure. Moreover, enantiomers of chlorthalidone were determined in two commercially available pharmaceuticals.
The proposed method may be easily transferred to a semi-preparative scale.