Development and Validation of Green Spectrophotometric Methods for Simultaneous Determination of Paracetamol, Pamabrom and Pyrilamine Maleate in Bulk and Pharmaceutical Dosage Form

Four simple and accurate spectrophotometric methods were developed for the simultaneous determination of paracetamol, pamabrom and pyrilamine maleate. The first is a zero order spectrophotometric method used for the determination of pyrilamine maleate in presence of paracetamol and pamabrom in the range of 0.5‐60 μg/mL by measuring the absorbance at 306.8 nm where paracetamol and pamabrom exhibits zero reading. The other three methods; bivariate, dual wavelength and area under the curve methods were developed for the simultaneous determination of paracetamol, pamabrom in presence of pyrilamine maleate. Bivariate calibration algorithm involves the use of two selected wavelengths; 260 nm and 280 nm for the determination of the two studied drugs. For the dual wavelength, paracetamol shows equal absorbance at 212.87 and 220.0 nm, where the differences in absorbance were measured for the determination of PBM. Similarly, differences in absorbance at 264.23 nm and 292.28 nm were measured for determination of paracetamol. In the area under curve method; the area between 237.14 to 247.14 nm was used for determination of paracetamol and 273.6 to 283.6 nm for pamabrom. Beer’s law was obeyed in the concentration ranges of 1-30 μg mL-1 for paracetamol and pamabrom in all methods. LOD was calculated and ranges from 0.149-0.766 μg/mL, while LOQ was found to be in the range of 0.556-1.145 μg/mL. The proposed methods were successfully applied for the simultaneous determination of PCM, PBM and PAM in their pharmaceutical preparation without interference from additives present with mean recovery ranging from 98.99 to 101.44%. Statistical analysis of the results obtained by the proposed spectrophotometric methods compared with a reported method revealed no significant difference between the proposed and reported methods confirming accuracy and precision at 95% confidence limit.