Exploring the aggregation behaviour and antibiotic binding ability of thiazolium-based surface-active ionic liquids; Understanding transportation of poorly water-soluble drug

Abstract

Despite significant advancements in drug delivery systems, researchers still face huge challenges in designing a suitable carrier for various drugs. Surface-active molecules having properties such as higher stability and non-toxicity can be used for sustained drug release. Herein, micellar aggregates of surface-active ionic liquids (SAILs) have been utilized, which exhibit a good ability to act as nanocarriers for poorly water-soluble drug molecules. Novel thiazolium-based SAILs, i.e., 3-dodecyl-5-(2-hydroxyethyl)− 4-methylthiazol-3-ium bromide [C12thia][Br] and 3-tetradecyl-5-(2-hydroxyethyl)− 4-methylthiazol-3-ium bromide [C14thia][Br] were synthesized and form self-assembled micellar nano aggregates in the aqueous phase. Their aggregation behaviour and interaction with poorly water-soluble antibiotic drug sulfamethoxazole (SMX) were monitored using conductivity, surface tension and isothermal titration calorimetric (ITC) techniques. The size distribution of formed aggregates was assessed using dynamic light scattering (DLS) and transmission electron microscopy (TEM). Their efficiency as nanocarriers for the drug molecules was explored by UV–vis spectroscopy. The mathematical drug release models show a sustainable release behaviour of the SMX drug molecules from the micellar matrix. Antibacterial activity was investigated on gram-negative and gram-positive bacterial strains by measuring the inhibition zone. Efficient drug loading and enhancement in the antimicrobial activity of SMX using nano-micelles of synthesized SAILs have been observed, indicating the scope and efficacy of novel thiazolium-based SAILs as promising candidates for drug delivery applications.