Development and Validation of a RP-HPLC Method for Simultaneous Quantification of Paracetamol and Phenylephrine Hydrochloride

A rapid, accurate, and sensitive method for the simultaneous quantification of paracetamol and phenylephrine hydrochloride was developed using RP-HPLC.The procedure utilized a NUCLEODUR® C18 separating column (250 × 4.6 mm id) with a flow rate of 0.8 mL/min and a column temperature of 25℃.The detector wavelength was set at 234 nm, and the injection volume was 20 μL.The mobile phase consisted of a mixture of acetonitrile and buffer solution (45 mM orthophosphoric acid, and the pH was adjusted to 6 using a 10% (w/v) sodium hydroxide solution) in a 52:48 v/v ratio.The method was validated with recovery percentages ranging from 99.36 to 105% for paracetamol and 99.78 to 100.8% for phenylephrine.The correlation coefficients were 0.9999 for both compounds, with linearity ranges of 2-100 µg/mL for paracetamol and 5-80 µg/mL for phenylephrine.This method has been successfully applied to the simultaneous quantification of these drugs in pharmaceutical preparations available in the local market.