Simultaneous Spectrophotometric Estimation of Diclofenac Sodium and Omeprazole in Capsules

Two simple, sensitive, rapid spectrophotometric methods have been developed for simultaneous estimation of diclofenac sodium (DFS) and omeprazole (OME) in capsules. First method involves solving simultaneous equations based on measurement of absorbance at two wavelengths 248.0 nm and 301.5 nm λ max of DFS and OME, respectively. Second method involves formation of Q-absorbance equation at 255.5 nm (isoabsorptive point) and 301.5 nm (λ max of OME). Beer's law was obeyed in the concentration range of 10-50 μg/ml and 5-25 μg/ml for DFS and OME, respectively. The methods were validated as per ICH guidelines. Statistical analysis proved that the methods were accurate, precise, and reproducible for analysis of DFS and OME in capsules. The wide linearity range, sensitivity, accuracy and simple procedure imply that the proposed technique demonstrated to be appropriate for routine analysis and quality control assay of capsules.