Development of Indirect Spectrophotometric Method for the Estimation of Oxymetazoline Hydrochloride as Pure Formand in its Pharmaceutical Preparations

This method involves the development of a highly sensitive spectrophotometric procedure for estimating oxymetazoline hydrochloride in pure form and pharmaceutical formulations. The method involved the oxidation of oxymetazoline hydrochloride with an excess amount of cerium sulfate (CeSO4) in an acidic medium. The liberated cerium ion Ce(III) was then treated with arsenazo III reagent to form a colored complex with maximum absorption at 652 nm. The linearity of the standard calibration curve follows Beer's law in the concentration range of 1.25 to 12.5 μg/mL of oxymetazoline hydrochloride with a correlation coefficient of 0.9993 and molar absorptivity of 2.25×104 L.mol-1.cm-1. The Sandell's sensitivity index was estimated and found to be 0.0147 μg/cm2. The limit of detection (LOD) and limit of quantitation (LOQ) were also calculated and found to be 0.3036 and 0.9824 μg/mL, respectively. The precision (RSD%) and the error percentage were also estimated and found to be in the ranges of ±0.446 to ±0.659 and -1.03% to 0.58%, respectively. The recommended procedure has been applied to estimate oxymetazoline hydrochloride in obtainable dosage forms (drops and sprays).