Research

Abstract:

Two-dimensional diffusion ordered spectroscopy (DOSY) ¹H NMR is proposed to analyze drugs that are complex mixtures in order to discriminate genuine from fake formulations. The method was applied to the analysis of 17 formulations of sildenafil, one being genuine Viagra and the others illegally manufactured formulations of this drug coming from India, Syria and China. It enabled (i) distinguishing imitations or counterfeit from the authentic formulation, (ii) detecting the presence of sildenafil or adulterants, (iii) gaining information on the formulation process by detection of various excipients, thus giving a precise and global ‘signature’ of the manufacturer. Even though some samples are slightly overdosed, the quality of products manufactured in India and Syria was better than that of Chinese formulations which were adulterated with vardenafil and homosildenafil. This study also presents a three-dimensional DOSY-COSY ¹H NMR experiment that provides both virtual separation and structural information. 

Name of journal in which the research was published: 

Magnetic Resonance in Chemistry.

Publication Date:

2009.

Link:

The usefulness of 2D DOSY and 3D DOSY-COSY 1H NMR for mixture analysis: application to genuine and fake formulations of sildenafil (Viagra)