Abstract

Simple, sensitive and reproducible spectrophotometric method was developed for estimation of oxymetazoline hydrochloride via charge
transfer complex formation reaction. The method is based on the reaction of oxymetazoline as n-donor with DDQ reagent as π-acceptor in
basic aqueous medium of pH 9.79. The maximum absorption is 421 nm. Beer's law was obeyed in the range 0.4-4.0 µg mL-1 with molar
absorptivity 2.5 x 104 L mol-1 cm-1
. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.0093 and 0.028 µg mL-1
respectively. The stability constant has been determined and the mechanism of the reactions was proposed. The proposed method was
applied to determine the oxymetazoline hydrochloride in dosage form as drop, and the results were statistically compared with official BP
method.

Key words: oxymetazoline, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), spectrophotometry, charge transfer complex