Optimization of the separation of salbutamol and its decomposition products by liquid chromatography with diode-array detection.

A high-performance liquid chromatographic (HPLC) method based on diode-array detection is developed and optimized for stability studies on salbutamol. In establishing the method, the effects of mobile phase constituents (buffers, buffer concentration, pH, modifiers, organic solvents, ion-pair reagents) upon the resolution of salbutamol and its degradation products are studied. The optimum method involves the use of a LiChrosorb RP-18 column with a one-step gradient elution with acetonitrile-sodium dihydrogen phosphate (40 mM)-triethylamine (5.74 mM) (pH 3.0). The acetonitrile content is increased from 4 to 9% after 6 min.