الملخص

Abstract A simple spectrophotometric method for the simultaneous kinetic determination of Paracetamol (PAR) and Salicylamide (SAL) by applying the H-point standard addition method (HPSAM) has been developed. The method depends on the difference in the oxidation time of the two medicinal compounds by the ferric ion Fe(III) and the reaction of the resulting ferrous ion Fe(II) with 2,2’-bipyridyl reagent (BPY) reagent to form an orange complex that has a maximum absorption at 522 nm. PAR as analyte and SAL as interferent were determined in the mixture, Beer's law applies within concentrations 1-5 μg.mL-1 for PAR and 10-90 μg.mL-1 for SAL in their mixture, with weight ratios of 1:90 and 5:20 PAR: SAL, relative standard deviation range between1.04 and 2.4 and a recovery % ranging from 98.2%-102.1%, at the pair time t6-t16, indicating that the method is precise and accurate. It should be corrected as: The method is free from interferences due to the excipients present in pharmaceutical formulation The method is free from excipients present in pharmaceutical formulation. The proposed method was also successfully applied for the determination of PAR and SAL in pure forms and synthetic pharmaceutical preparation as Rinomicine.