Determination of omeprazole in pharmaceuticals by derivative spectroscopy

A new derivative UV spectroscopic method was developed for the analysis of omeprazole in borate buffer (pH 10.0; 0.1 M). Second derivative spectra were generated between 200-400 nm at N = 9, delta gamma = 31.5. The linearity range for values obtained from second derivative spectra was 0.2-40.0 micrograms ml-1. The developed method was applied to five different commercial preparations of hard gelatin capsules containing enteric coated granules. The relative standard deviations were found to be 2.24% (brand A), 1.87% (brand B), 2.80% (brand C), 4.55% (brand D) and 1.09% (brand E). The data were compared with ones obtained from the polarographic method given in the literature and no difference was found statistically.