Simple and rapid determination of a new pharmaceutically active amine hydrochloride

The quantitative analysis of a new pharmaceutically active amine hydrochloride is described. Samples are extracted with chloroform. A yellow amine-dye complex is formed by buffering a sample-bromthymol blue solution at pH 8.5 +/- 0.1 and subsequently extracted with chloroform. The complex is treated with 0.01 N NaOH to convert it back to the sodium salt of bromthymol blue, which is then measured at 615 nm in the aqueous layer. The amount of complex extracted is linearly related to the amount of amine present, from 0.020 to 0.20 mg/ml. Under the selected conditions, the compound can be determined in the presence of degradation products and there is no interference from common pharmaceutical excipients. The method is suitable for stability studies.