Simultaneous Determination of Diclofenac and Esomeprazole by Reversed phase Liquid Chromatography, Dual Wavelength and Derivative Spectrophotometry

Resumo

Three methods were developed for simultaneous determination of diclofenac and esomeprazole in their binary mixtures. Method I is dual wavelength spectrophotometry which is based on measurement of absorbance difference ΔA (281.7–315 nm) for determination of diclofenac and ∆A (262.6–301.6 nm) for determination of esomeprazole. Method II is derivative spectrophotometry which is based on measuring ¹D at 301.6 nm for determination of diclofenac and ²D at 299.5 nm for determination of esomeprazole. Linearity ranges were found to be 5–25 and 2‒10 μg/mL for diclofenac and esomeprazole, respectively, using methods I and II. Method III is reversed phase HPLC method which involves separation of diclofenac and esomeprazole on XBridge^TMC18 column using a mobile phase consisting of ethanol-phosphate buffer solution (pH 4, 60 : 40, v/v). The flow rate was 1.5 mL/min with ultraviolet detection at 290 nm. The calibration graphs are linear from 2 to 120 μg/mL for diclofenac and from 5 to 60 μg/mL for esomeprazole.