Terbium Sensitized Chemiluminescence Method for the Determination of Rabeprazole -Application to Pharmaceutical Analysis and Dissolution Studies

A simple and sensitive chemiluminescence-based method was established for the determination of rabeprazole.The proposed method was based on the enhancing effect of rabeprazole on Ce(IV)-Na2SO3 -Tb(III) chemiluminescence reaction. A possible mechanism was discussed for chemiluminescence system by studying UV-Vis, fluorescence and chemiluminescence spectra. The effects of various chemical parameters were investigated and optimized. Under the optimum conditions, the enhanced chemiluminescence intensity was directly proportional to the concentration of rabeprazole in the range of 0.015-0.2 µg ml-1, with a detection limit of 6 ng ml-1. The proposed method was applied to the analysis of pharmaceutical formulations and human plasma samples and to the dissolution study of rabeprazole tablets with satisfactory results. The results indicated that more than 95% of the labeled amount of rabeprazole was dissolved over 30 min in the basic medium, while only 10% of rabeprazole was released in acidic medium.