ENANTIOMERIC SEPARATION OF SALBUTAMOL AND RELATED IMPURITIES USING CAPILLARY ELECTROPHORESIS

The enantiomeric resolution of salbutamol and its chiral and achiral r elated impurites is investigated using capillary electrophoresis. The effects of nine varieties of cyclodextrin, cyclodextrin concentration and organic modifier concentration were studied in an attempt to resol ve all possible analytes in a complex mixture of salbutamol-related so lutes. Eleven components including three enantiomeric pairs were basel ine resolved using 112 mM dimethyl-beta-cyclodextrin at pH 2.5 in a ci tric acid/phosphate buffer. Both methanol and iso-propyl alcohol at up to 20% were found to have a deleterious effect on the separation. Bin ding constants and mobility values for the free and complexed forms fo r each solute were determined. The results are interpreted by consider ing the physical properties of the molecules under the conditions empl oyed and a rationale proposed for the underlying basis for chiral and achiral selectivity.