Revathi Gunji, Rama Rao Nadendla, Venkata Suresh Ponnuru
A novel, simple, safe, sensitive, and economical method of spectrophotometric estimation in UV region has been developed using 5M urea solution as hydrotropic solubilizing agent for the quantitative determination of Rabeprazole sodium and Diclofenac sodium. Two methods are described for the simultaneous determination of Rabeprazole sodium and Diclofenac sodium in combined pharmaceutical tablets. Urea did not show any absorbance above 225nm, there was no interference during estimation of Diclofenac and Rabeprazole. The first method is simultaneous estimation using vierodt’s equation where absorption maxima found at 285nm and 276nm for Rabeprazole and Diclofenac, respective’ly. The second method is based on Q-Absorption ratio method using two wavelengths, at 281nm (Isobestic point) and 276nm (λmax for Diclofenac). Two methods follow Beer’s linearity in the range of 4-28μg/ml and 5-25μg/ml with correlation coefficient r2 of 0.999 and 0.998 for Rabeprazole and Diclofenac, respectively. According to ICH norms the parameters linearity, precision, accuracy, limit of detection, and limit of quantification were studied, the results of analysis were validated statistically and by recovery studies. The proposed methods were simple, cost effective and were successfully applied to the determination of these drugs in quality control of combined pharmaceutical dosage
