Diffusion ordered NMR spectroscopy measurements as screening method of potential reactions of API and excipients in
Alexander Becht1, Curd Schollmayer1, Johannes Wiest1
1University of Würzburg, Institute for Pharmacy and Food Chemistry, 97074, Würzburg, Germany.
Abstract:
In the development of new pharmaceutical formulations it is important to consider the possible interactions between the active pharmaceutical ingredient (API) and excipients which is a well-known problem. The objective of the work presented here was to investigate such reactions by means of diffusion ordered NMR spectroscopy (DOSY). The known reaction of 5-aminosalicylic acid (5-ASA) and the excipient citric acid was studied. Three reaction products have been verified by DOSY, 1H NMR and HPLC measurements. Despite a poor separation in the DOSY diagram, the reaction products could be assign due to the processing of thoughtful selected parts of the signals. The reaction of 5-ASA with formic acid and benzocaine with dibutyl phthalate was also studied by means of DOSY experiments.
Related Concept Videos
Measuring Reaction Rates
NMR Spectroscopy Of Amines
NMR Spectroscopy of Aromatic Compounds
NMR Spectroscopy of Benzene Derivatives
NMR Spectroscopy: Chemical Shift Overview
For instance, the proton...
NMR Spectroscopy: Spin–Spin Coupling


