Adsorption of Sulfonamides on Phyllosilicate Surfaces by Molecular Modeling Calculations

Sulfamides belong to a great group of antibiotics used for decades for human therapeutics and farm livestock. This intensive use has generated an important environmental risk due to the presence of these compounds in wastewaters and soils close to worldwide farm industries. The molecular structure and physicochemical properties of these molecules are interesting for evaluating the molecular interactions with surfaces of clay minerals. These interactions are important to know the mobility of these compounds through soils and to design new nanomaterials for drug delivery. The molecular structure and conformational analysis of the sulfonamides, sulfamethoxypyridazine and sulfamethoxydiazine, as models of sulfonamides, have been studied with quantum mechanical calculations and force fields based on empirical interatomic potentials calculations. The adsorption of these drugs on a phyllosilicate surface of (001) plane has been investigated, finding that it is an exothermic process for both sulfonamides.