Comparative Chiral Separation of (RS)‐Propranolol Racemate by HPLC Using α-Glycoprotein and β-Cyclodextrin Stationary Phases.

Abstract

The most of the β-blockers are still clinically being sold as a racemic mixture despite the fact that their enantiomers show significant differences in the pharmacological effects and activities. This paper describes a comparative study of tow chiral separations of (RS)‐Propranolol racemate by HPLC using α-Glycoprotein (AGP) and β-Cyclodextrin (BCD) Stationary Phases. For the AGP separation, the column size was (150 mm X4 mm X 5 μm), the mobile phase composed of Propanol-2 and Ammonium acetate (0.5:99.5 v/v), at a flow rate of 0.9 mL/min and the detection by ultraviolet absorption at 225 nm. For the BCD separation, the column size was (200 mm X4 mm X 5 μm), the mobile phase composed of Acetonitrile: Ethanol: Acetic acid: Triethylamine (960: 33: 4: 3 v/v/v/v), at a flow rate of 1 mL/min and the detection by ultraviolet absorption at 225 nm. The retention time of SPropranolol and R-Propranolol with AGP separation was respectively: 7.25 min and 11.82 min while with the BCD separation 16.18 min and 18.50 min respectively. The racemate contains 50.46 % of S-Propranolol and 49.53 % of R-Propranolol with AGP separation while with BCD separation, it contains 50.43 % of S- enantiomer and 49.57 % of R-enantiomer. There is a similarity between the enantiomeric purity values and the enantiomeric excess values of tow separations, but the separation with AGP stationary phase is faster than with the BCD stationary phase. For a selective β-blocking use, it could be very interesting to encourage its production in its form enantiomerically pure wich is the S-enantiomer.