Fast and Facile UV-Spectrophotometry-Assisted Chemometrics Methods for the Simultaneous Determination of Phenytoin and Phenobarbital as Antiepileptic Drugs in Combined Dosage form and Urine Sample

Phenytoin (PHT) and phenobarbital (PHB) are two antiepileptic drugs that are used simultaneously in tablet formulation. In this study, two simple, accurate, and precise multivariate calibration methods, including Net Analyte Signal (NAS) and Principal Component Regression (PCR) were described for the simultaneous spectrophotometric determination of PHT and PHB in Phenytoin Compound tablet and biological sample (urine). The linearity in the range of 1–8 μg/mL for PHT and PHB with an excellent R squared (R2) (PHT=0.9955, PHB=0.9948) was obtained in the NAS model. The Limit of Detection (LOD) Was 0.0954 And 0.1412 Μg/Ml, Whereas The Limit of Quantification (LOQ) was 0.2354 and 0.2882 μg/mL, respectively. The mean recovery of PHT and PHB-related to the mixtures was found to be 99.93% and 99.32% using the NAS model and 100.03% and 99.68% using the PCR method, with a low Root Mean Square Error (RMSE) (<0.04%). According to the analysis of the tablet sample, the results obtained by NAS and PCR were comparable with those obtained by the High-Performance Liquid (HPLC) chromatography technique. The suggested approaches permit concurrent determination of PHT and PHB in pharmaceutical form without interference from each other. Therefore, these methods can be considered for quality-control studies.