EXPERIMENTAL-DESIGN IN THE DEVELOPMENT OF VOLTAMMETRIC METHOD FOR THEASSAY OF OMEPRAZOLE

A multivariate strategy was used to optimize an adsorptive stripping v oltammetric method for the determination of the antiulcer drug omepraz ole. A 3/4 matrix was used for the variable screening while a central composite design was chosen in the subsequent step to evaluate the res ponse surfaces. Simultaneous optimization of the response peak height (h(p)) and peak half width w(1/2), the latter being a peak shape measu re, was achieved. The factors accumulation time, pulse amplitude, scan rate and stirring rate were all found to be statistically significant for the response h(p), while for the response iv,, only the stirring rate was found to be significant. The optimized method shows a good li nearity between peak height and analyte concentration in the concentra tion range from 8.33 x 10(-9) M to 1.42 x 10(-7) M with a LOD of 6.5 x 10(-9) M. The mean recovery of omeprazole in capsules was 101.9% with a SD of 2.04 (RSD = 200).