Spectrophotometric determination of phenylephrine hydrochloride in multi-component pharmaceutical preparations with fast violet B salt

ABSTRACT

A spectrophotometric method for the determination of phenylephrine hydrochloride is descried. The method involves formation of an intense red complex [lambda max 520 nm] due to reaction of the drug with zinc chloride salt of 4-benzoylamino-2-methoxy-5-methylbenzenediazonium chloride [fast violet B salt] in acidic medium. Beer's Law is obeyed over the concentration range 1-10 mug/ml of phenylephrine hydrochloride with a molar absorptivity of 2.03 x 10 4 l.mol -1 cm -1. The optimum conditions for full color development have been investigated. The proposed method has been applied to the analysis of some pharmaceutical preparations with good recoveries [98.8-101.2%]. No interference took place by common excipients, dyes and other drug compounds, likely to be present in preparations