Determination of Mexidol in tablets by the method of derivative spectrophotometry

Mexidol (3-hydroxy-6-methyl-2-ethylpyridine succinate) is a drug that exhibits neuroprotective, antihypoxic, anti-ischemic, nootropic, anti-stress and geroprotective effects and can suppress or slow down oxidation reactions. Оbjective: to develop a selective and simple method for assessing the content of mexidol in tablets. Materials and methods. The objects of the study were mexidol (3-hydroxy-6-methyl-2-ethylpyridine succinate) and Mexidol tablets 0.125 g. Derivative spectrophotometry was used as an analysis method. Results. The ability of mexidol to intensively absorb electromagnetic radiation in the quartz ultraviolet region was revealed. This phenomenon is due to the fact that the analyte molecule contains a number of chromophore groups: a system of conjugated aromatic bonds of the pyridine ring, unpaired electrons at the nitrogen atom, and an enol hydroxyl conjugated with the aromatic system In the region of 292 nm, there is a linear dependence of the derivatives of the 2nd order of the specific absorption coefficient of mexidol on the amount of analyte in the photometric solution (range 2.5-50.0 μg/ml). A calibration graph has been constructed, and its equation has been calculated by the least-squares method. The correlation coefficient exceeds 0.999. The limits of detection and quantification are 1.25 and 2.5 µg/ml, respectively. The technique is characterized by the necessary reproducibility and correctness. The values of the standard deviation and relative standard deviation in the determination of the analyte using the proposed method (n=6; P=0.95) in the tablet mass are 1.16 and 0.012, respectively, in tablets of 0.125 g, 1.32 and 0.013, respectively. Conclusion. A simple and selective method has been developed for estimating the quantitative content of mexidol in 0.125 g tablets based on the calculation of second-order derivatives of spectra.