Development of the spectrophotometric method for the determination of metoprolol in tablets by using bromophenol blue

Abstract

The aim of the work was to develop a simple, economical and eco-friendly spectrophotometric method for determining metoprolol tartrate in tablets based on the reaction with bromophenol blue (BPB). Material and methods: A double–beam Shimadzu UV-Visible spectrophotometer, with a spectral bandwidth of 1 nm wavelength accuracy ±0.5 nm, Model –UV 1800 (Japan), Software UV-Probe 2.62, and a pair of 1 cm matched quartz cells, was used to measure the absorbance of the resulting solution. All the chemicals were used in analytical reagent grade. Pharmacopeial standard samples of metoprolol tartrate and bromophenol blue (BPB) were provided by Sigma-Aldrich (≥ 98%, HPLC). The used dosage forms of metoprolol tartrate are tablets of Metoprolol 50 mg and 100 mg. Results and discussion: The method of spectrophotometric determination of the quantitative content of metoprolol tartrate based on its reaction with BPB in a methanol solution has been developed. The stoichiometric ratios of the reactive components as 1:1 were obtained by the methods of continuous changes and the saturation method. The developed method of quantitative determination of metoprolol tartrate was validated. The linearity regression equation was y = 0.0373x + 0.0038, and the obtained correlation coefficient was R2=0.9984. A linear relationship was found between absorbance at λmax and concentration of metoprolol tartrate in the range of 9.56-15.02 µg/mL. The LOD and LOQ values were calculated to be 0.81 µg/mL and 2.67 µg/mL. Conclusions. A simple, economical and eco-friendly spectrophotometric method has been developed for the quantitative determination of metoprolol tartrate in tablets based on the reaction with BPB. The developed method of quantitative determination of metoprolol tartrate was validated in accordance with the requirements of SPhU. We suggest our work with offered detailed and successful solutions for the mentioned aim with less sophisticated equipment for QC lab for routine manufacturing control