A green validated HPLC-UV Method for determining and quantifying pholcodine, paracetamol, and pseudoephedrine in laboratory-prepared mixtures and their FDC capsule

• Rapid Analysis : Retention times were optimized for quick separation: 0.8, 1.9, and 3.0 minutes for pholcodine, paracetamol, and pseudoephedrine, respectively, ensuring a highly efficient analysis in comparison with the only reported method with retention times of 3.8, 9.4, 15.6 minutes for paracetamol, pseudoephedrine and pholcodine respectively. • Wide Applicability : Demonstrated method suitability for different sample types, including laboratory-prepared mixtures and commercial dosage forms, enhancing its versatility in pharmaceutical analysis. • Precision and Accuracy : Intraday and interday relative standard deviation (RSD) values were less than 1%, with mean recoveries close to 100%, reflecting the method's high reliability. • Environmental Greenness Metrics : The method's environmental impact was evaluated using five tools (Eco-Scale, NEMI, AGP, GAPI, AGREE), achieving superior eco-friendliness compared to reported methods. A validated technique has been developed for the sequential determination of pholcodine, paracetamol, and pseudoephedrine. This method allows for their separation either in different ratios within a ternary mixture or in their fixed-dose combination (FDC) using HPLC. The chromatographic conditions involved the utilization of an X-select C 18 column (5µ, 4.6*150 mm) and a mobile phase consisting of 0.05 M KH 2 PO 4 : Methanol (75:25, v/v), with orthophosphoric acid added to adjust the PH to 2.6. The separation was conducted at a 1.2 ml/min flow rate, while a UV detector was set at a wavelength of 206 nm to monitor the process. The three drugs were successfully eluted with retention times of 0.8, 1.9, and 3.0 min for pholcodine, paracetamol, and pseudoephedrine respectively providing fast analysis times. The method exhibited linearity for pholcodine, paracetamol, and pseudoephedrine over concentration ranges of 12-200 µg/ml, 5-100 µg/ml, and 30-200 µg/ml, respectively. It was accurate, reliable, and precise (RSD < 2%). This proposed methodology was effectively implemented to quantify the concentration of pholcodine, pseudoephedrine, and paracetamol in freshly prepared mixtures and pharmaceutical dosage forms. Furthermore, the method's environmental impact was assessed using five different tools, demonstrating low hazard levels to the environment, and promoting its environmental friendliness compared to the reported method.