Application of experimental design to the development of a multicomponent derivative spectrophotometric method: simultaneous determination of sulfamethoxazole and trimethoprim

Abstract

A central composite design is used for the development of a spectrophotometric method for the simultaneous determination of sulfamethoxazole and trimethoprim. The method involves multicomponent second-derivative spectrophotometry in the ultraviolet range with a photodiode-array spectrophotometer. Accuracy, precision, linearity and other figures of merit are verified in connection with the application of the proposed method to pharmaceutical quality control. The influence of such variables as wavelength range, derivative order and solvent are discussed.