Interaction Between an Active Pharmaceutical Ingredient Ionic Liquid Benzalkonium Salicylate and Small Biomolecules in Aqueous Solution: UV Absorption, Conductivity, and Volumetric Study

摘要

UV absorption spectroscopy, electrical conductivity and density experiments have been used to investigate the interactions of some small biomolecules (amino acids/dipeptides) with an active pharmaceutical ingredient in ionic liquid form (API-IL), benzalkonium salicylate (BaSal), in aqueous solution. A number of useful parameters, such as critical micellar concentration (cmc), aggregation number (N-agg) and limiting molar conductivity ((0)) of BaSal, standard partial molar volumes hydration number (n(H)) of small biomolecules, as well as the binding constants (K-b) for small biomolecule-BaSal complexes have been evaluated. The dependence of the properties on concentration, temperature and alkyl chain length of amino acids/dipeptides is examined. The results are used to identify the solute-solvent physicochemical interactions occurring in the studied systems.