Applicability of Derivative Spectrophotometry, Bivariate Calibration Algorithm, and the Vierordt Method for Simultaneous Determination of Ranitidine and Amoxicillin in Their Binary Mixtures

Ultraviolet (UV)-derivative spectrophotometry, bivariate calibration algorithm, and Vierodt methods were applied to simultaneous determination of ranitidine (R) and amoxicillin (AMX) in binary mixtures. The first-order derivative allows determination of R in the concentration range 4.010-6moldm-3 to 6.010-5moldm-3. Vierordt method enables Ranitidine assaying in the presence of 2.5-fold excess of AMX and 3-fold excess of R. The bivariate calibration method obeys Beer's law in the concentration ranges 4.010-6moldm-3 to 6.010-5moldm-3 for R and 2.010-6 to 2.010-5moldm-3 for AMX.