Spectrophotometric Assay for the Determination of Phenylephrine-HCl using Sodium Nitroprusside and Hydroxylamine Hydrochloride as a reagents

Abstract

This study addressed a straightforward, precise and easy spectrophotometric method to determine phenylephrine hydrochloride (PHP) in bulk and pharmaceuticals dosage (drops and syrup). This method involves the interaction of sodium nitroprusside (SNP) with phenylephrine hydrochloride and hydroxylamine hydrochloride (HAH) in a phosphate buffer solution (pH 12) to produce a green color product. The overlain spectra of the product showed maximum PHP absorption at 714nm. The absorbance was started to increase linearly with the increased concentration of PHP. Under the optimal conditions, Beer’s law has been obeyed within the concentration range 0.2 – 8µg/mL. The developed method has good accuracy (average recovery) of 101.04% and precision (RSD) is less than 1.2%. with molar absorptivity 4.4610x104 L.mol-1.cm-1. The detection limit (LOD) and limit of quantification limit (LOQ) were 0.047 and 0.155ng/mL respectively. The suggested approach was applied practically to the determination of PHP in drug products (drops and syrup) with good precision and sensitivity. In addition, the validity of the suggested procedure was confirmed by the standard addition method. The advanced spectrophotometric procedure for assay of PHP is precise, simple, and reproducible with inexpensive and quite safe solvents. It could be applied in principles and practice for routine work analysis of PHP in bulk and pharmaceutical dosages.