Co-Crystallization of the Anti-Cholesterol Drug Bezafibrate: Molecular Recognition of a Pharmaceutical Contaminant in the Solid State and Solution via Hydrogen Bonding

Pharmaceuticals have been found as contaminants in wastewater, causing concern for the health of aquatic life and humans. The anti-cholesterol medication bezafibrate is one such contaminant and is difficult to remove from wastewater. The lack of studies investigating the bonding behavior of bezafibrate with potential acceptor motifs prompted us to determine the types of molecules that would engage in intermolecular bonds with the drug. Although co-crystallization of bezafibrate has been previously attempted, we altered the approach by utilizing molecules containing only hydrogen-bond-acceptor sites. Here, we discuss the first successful co-crystallizations of bezafibrate, intermolecular bonding behavior, and solution-state binding studies with potential acceptor molecules. One acceptor, 4-dimethylaminopyridine, exhibits a shorter bond in the solid state, and a solution-state binding constant over 18 times higher than any other drug-acceptor pair studied here. These studies should aid in designing contaminant-removal materials that will effectively bond with the drug.