Colorimetric Determination of Terbutaline and Orciprenaline Through Nitration and Subsequent Treatment with Acetyl Acetone in Alkaline Medium

A colorimetric method is proposed for the determination of terbutaline sulphate, orciprenaline sulphate and their dosage forms. The procedure is based on the formation of trinitroderivatives of the drug which are subsequently subjected to a charge transfer complexation reaction with a donor, acetyl acetone. Concentration ranges adhering to Beer's Law are 4–32 μg/ml for both. The proposed method has been applied to pharmaceutical preparations and has proven to be accurate and precise.