Spectrophotometric and colorimetric determination of etilefrine hydrochlo oride and oxedrine tartrate

Simple, rapid and accurate spectrophotometric and colorimetric methods were presented for the determination of etilefrine HCl and oxedrine tartrate. The first was based on the measurement of the absorbance difference [delta A] in alkaline and acid media. The second was based on the reaction of these drugs with 3-methyl-2-benzothiazolone hydrazone HCl in the presence of cerric ammonium sulfate and involved the direct absorbance measurement of the color product at 480 nm