An Analytical Evaluation of the Separation and Identification of Certain Decongestants and Cough Suppressants in Pharmaceutical Preparations Using Modern Analytical Techniques

Here, we describe an analytical method for the separation and measurement of certain decongestants and cough suppressants, specifically phenylephrine hydrochloride in both free and prescription forms. Hydrochloric acid was used as the acid medium to optimize the oxidative coupling reaction with para-aminophenol in the presence of potassium iodide. Various reagent types and volumes, oxidizing agents, acid concentrations, temperatures, reaction times, and stability were systematically investigated. The approach exhibited perfect linearity in the scope of 2–50 μL at λmax = 548 nm with acceptable accuracy and sensitivity. When applied to a commercial syrup, it provided high values of recovery with no sign of substantial interference by.