First Derivative Spectrophotometric Determination of Certain Drugs in Two-Component Mixtures

Four two-component mixtures have been assayed using both Vierordt's and first derivative spectrophotometric methods. Such mixtures are acepifylline and phenobarbitone, phenylbutazone and amidopyrine, procaine and caffeine, and sulphamethoxazole and trimethoprim. These selected applications illustrate the relative ease and simplicity offered by first derivative spectrophotometry for the assay of two component mixtures with spectral interferences from matrix formulations.