Three New Methods for Resolving Ternary Mixture with Overlapping Spectra: Comparative Study

In this study three new spectrophotometric methods have been developed and validated for simultaneous determination of ternary mixture of metronidazole (MET), diloxanide (DLX) and mebeverine HCl (MEB) without prior separation steps. The newly introduced methods consisted of several steps utilizing either zero order or ratio spectra without the need for derivatization steps. The developed methods are called area under the curve (“AUC”), modified absorption factor (MAFM) and modified amplitude center (MACM) spectrophotometric methods. Selectivity and validity of the methods were checked by using different synthetic mixtures and by analysis of their combined dosage form where low standard deviation values and good percentage recoveries were obtained. Additionally, methods linearity, accuracy and precision were determined following United States Pharmacopoeia (USP) recommendations. The obtained results were found to agree with the reported ones when they were statistically compared using One Way ANOVA test. These methods are easily applied during drug quality control studies and in laboratories lacking the facilities of chromatographic methods of analysis. Data manipulation steps are very simple, hence these methods can be considered as time and money saving methods comparing to chromatographic methods of analysis.