Spectrophotometric Determination of Salbutamol Sulphate by Coupling with Diazotized 5-Amino-2-chlorobenzotrifluoride – Application to Pharmaceutical Preparations

A simple, rapid and sensitive spectrophotometic method for the estimation of trace amounts of salbutamol sulphate (SBS) in pharmaceutical preparations has been proposed .The method is based on the coupling reaction of the intended compound with diazotized 5-amino-2-chlorobenzotrifluoride in alkaline medium and in the presence of Triton X-100 to form a yellow-orange dye that shows maximum absorption at 467 nm. Beers law is obeyed over the range 5 300 g / 10 ml (i.e.,0.5-30 ppm) with a molar absorptivity of 4.20 104 l.mol-1.cm-1 and Sandells sensitivity index of 0.0139 g.cm-2, a relative error of +1.08 to +3.46 % and a relative standard deviation of 0.76 to 3.50 %, depending on the concentration. The method has been applied to estimate salbutamol sulphate in syrup, tablet and ventolin.