Green Development of Polymeric Dummy Artificial Receptors with Affinity for Amide-Based Pharmaceutical Impurities

A simple, clean, and sustainable technology has been applied to the development of amide-based artificial receptors for the pharmaceutical impurity acetamide. Artificial receptors in the form of analogue template molecularly imprinted polymers (AT-MIPs) were produced in a supercritical carbon dioxide medium using methacrylamide and ethylene glycol dimethacrylate as the functional monomer and the crosslinker, respectively. AT-MIPs were obtained in high yields as easy-to-handle and ready-to-use solids. The materials were characterized by Fourier transform infrared spectroscopy, nitrogen adsorption porosimetry, scanning electron microscopy, and Morphologi G3 particle size analysis. The affinity properties of AT-MIPs for three amides (acetamide, benzamide, and pivalamide) were assessed by packing the affinity materials into blank columns and evaluating their profiles under static and dynamic modes. The size and shape of the cavities created on the artificial receptors had a strong impact on the material's performance. The results suggest a potential use of three-dimensional-shaped artificial receptors as efficient devices for the removal of amide-based compounds, whose dimensions are equal to or lower than those of the template molecule, from pharmaceutical crude mixtures.