Comparison between UV spectrophotometric and capillary electrophoresis methods for determination of rabeprazole sodium in pharmaceutical formulations

Rabeprazole sodium (RAB) is an anti-secretory agent which inhibits the enzyme H⁺ /K⁺ ATPase, present in the stomach parietal cells. The aim of this work is to develop and validate a simple and fast ultraviolet spectrophotometric method (UV) for quantification of RAB in pharmaceutical formulation and compare it with a capillary electrophoresis (CE) one, previously validated. The UV technique was applied using water (pH 10.0) as diluent and the determinations were made at λ = 291 nm. The method showed good linearity (r = 0.9997) in the concentration range of 6.0 to 18.0 μg ml^-1 .(The intra- and interday precision data demonstrated the method has good repeatability (RSD = 0.52 and 0.82, respectively . Accuracy and specificity were also evaluated and results were satisfactory. The detection and quantitation limits were 0.32 and 0.95 μg ml^-1 , respectively. Both methods demonstrated to be adequate for the intended purpose. Colegio de Farmacéuticos de la Provincia de Buenos Aires