Robust RP-HPLC method for the parallel determination of quaternary mixture in cold and cough syrups with sustainability appraisal.

A viral infection can cause colds and coughs, which are common respiratory ailments. A robust and efficient RP-HPLC method was proposed for the concurrent determination of guaifenesin (GUF), ephedrine (EPD), diphenhydramine (DPH), and dextromethorphan (DEX) in pharmaceutical formulations. The study attempted to design seven ecologically friendly tools using green and white measures to assess the environmental effects of inventive and forthright RP-HPLC strategies for analyzing and separating the quaternary mixture under its marketed form. The method employed an Inertsil ODS-3 V column (150 mm × 4.6 mm, 5 μm) with a mobile phase consisting of methanol, water, and dioctyl sodium sulfosuccinate. The optimal wavelength for detection was set at 250 nm, and the flow rate was maintained at 2.0 mL/min. As a result, the limits of detection (LOD) and quantification (LOQ) were calculated to be satisfactory. The calibration curves were established in the 3–80 µg/mL range to investigate the linearity with R2 > 0.999. Recovery studies confirmed the method’s trueness and significant results were demonstrated within the acceptable range of 98–102%. The study was assured according to ICH parameters, demonstrating excellent linearity and robustness.