Spectrophotometric determination of Salbutamol sulphate by coupling with diazotized 2,4-dinitroaniline

ABSTRACT<br /> A quick, convenient and sensitive method has been developed for the determination of microgram amounts of salbutamol sulphate in its pure form and pharmaceutical preparations. The method is based on the coupling reaction of the drug with diazotized 2,4 - dinitroaniline reagent in an alkaline medium to produce an intense blue coloured Water soluble and stable azo dye which exhibits a maximum absorption at 558 nm. Beer's law was obeyed over the concentration range 0.2 - 6 µg/ml with a molar absorptivity of 9.33×104 L.mol-1.cm-1 and Sandell's sensitivity index of 0.0061 g/cm2. The limit of detection is 0.0089 µg/ml while the limit of quantitation is 0.029 µg/ml. The method shows high accuracy (average recovery 99.75%) and precision (relative standard division (RSD) is less than 2.2%.The suggested procedure was applied for determination of salbutamol sulphate without any interference from common pharmaceutical excipients. The proposed method is successfully compared with the official method.