Spectrophotometric microdetermination of phenylephrine hydrochloride in pure and in pharmaceutical formulations using haematoxylin

A simple, rapid, selective and sensitive method for the micro amount determination of phenylephrine hydrochloride either in pure form (raw material) or in pharmaceutical formulations is described. The method is based on the development of violet colour charge transfer complex with haematoxylin in alkaline medium with 10 min after heating at 65 °C. The wavelength and maximum absorption range was found in the range from 640 to 620 nm. Molar absorptivity and Sandell sensitivity were found to be 2.38 × 104 L mol− 1 cm− 1 and 8.6 ng cm− 2 respectively. A linear correlation was found between absorbance (at the λmax) and concentration. The resulting colour is stable for more than 10 h. Results of the analyses of pure drug and dosage forms by the proposed method are in good agreement with those of the official BP 1998 procedure.