Quantitative analysis of complex antipyretic, analgesic, and anticatarrhal drugs by gradient HPLC techniques

Abstract

New analytical procedures using HPLC in the gradient mode have been developed for the quantitative analysis of multicomponent antipyretic, analgesic, and anticatarrhal drug compositions. Possibilities of the proposed method are demonstrated by the analysis of some existing and new preparations produced by the Leksredstva Co. In order to increase the chromatographic selectivity of codeine phosphate or ephedrine hydrochloride, it is suggested to introduce potassium phosphate in the mobile phase. In the absence of potassium phosphate, these components are irreversibly retained in sorbents of the Nova Pak C18 or Nucleosil C18 type. The salt is introduced into a mobile phase after the elution of all components other than codeine or ephedrine. This ensures highly effective separation of the peaks of codeine or ephedrine from those of other components, even present in much greater concentrations. Other advantages of the proposed methods are the one-stage procedure, short time, and high precision of analysis. The experimental data also promise good repeatability and reproducibility of the results, which will be substantiated by subsequent analyses of model mixtures containing both active and auxiliary components of ready-to-use medicinal forms.