RP‐HPLC enantioseparation of β‐adrenolytics using micellar mobile phase without organic solvents

AbstractEnantioseparation of a few commonly administered racemic β‐adrenolytics (namely, carvedilol, betaxolol, salbutamol and bisoprolol) has been achieved using a water micellar mobile phase containing surfactants (sodium dodecyl sulphate and Brij‐35) without organic solvents as a new approach in RP‐HPLC. Two chiral derivatizing reagents based on enantiomerically pure (S)‐(−)‐levofloxacin were synthesized using N‐hydroxysuccinimide and N‐hydroxybenzotriazole as the activation auxiliaries. Diastereomeric derivatives of the chosen β‐adrenolytics were synthesized under microwave irradiation in a very short reaction time. The (S)‐(−)‐levofloxacin moiety enhanced molar absorbance of the diastereomeric derivatives resulting in very low limit of detection (1.618 and 4.902 ng/mL, respectively, for diastereomeric derivatives of (RS)‐betaxolol and better resolution with lower retention times (for all the analytes), in comparison to literature reports. There was 15–20 times less consumption of mobile phase because of lower retention time.