HPLC versus SFC for the determination of salbutamol sulphate and its impurities in pharmaceuticals

A method to determine salbutamol sulphate and six impurities: 5-formyl-saligenin, salbutamol ketone, salbutamol bis ether, isopropyl salbutamol, desoxysalbutamol sulphate and salbutamol aldehyde, using reverse phase high performance liquid chromatography (RP-HPLC) with diode array detection (DAD) is proposed. The best separation was achieved using a gradient of 0.1 M ammonium acetate pH 3.0 and acetonitrile. When the procedure was applied to the analysis of tablets and cough syrups, the versatility of the HPLC method was higher than one based on supercritical fluid chromatography (SFC). When using the later method the excipient difficulted the identification and quantification of some compounds in cough syrup samples.