Studies on the interactions of some small biomolecules with antibacterial drug benzethonium chloride and its active pharmaceutical ingredient ionic liquid (API-IL) benzethonium L-proline at varying temperatures

From the conductivity, density and spectroscopy measurements, the interactions of benzethonium chloride ([BTC]) and its active pharmaceutical ingredient in ionic liquid format benzethonium L-proline ([BT][PRO]) with some amino acids and glycyl dipeptides have been examined. A number of useful parameters, such as standard partial molar volume (V2, ϕo), partial molar transfer volume (ΔtVo), standard partial molar expansibility (Eϕo) of these small biomolecules, critical micelle concentration (cmc), aggregation number (Nagg), thermodynamic micellization parameters of [BTC]/[BT][PRO], as well as binding constant for small biomolecule-drug complex have been evaluated. Group contributions of charged end group (NH3+, COO−), CH2 and (CH2CONH) groups of amino acids/dipeptides to V2, ϕo values have also been perceived. These parameters are helpful to study the structure making capacity of small biomolecules, solvation behavior of [BTC]/[BT][PRO] and various interactions present in the studied ternary solution. The interaction difference of [BTC] and [BT][PRO] with small biomolecules was studied.