Lauric arginate complexes with hydroxypropyl-β-cyclodextrin as a novel emulsifier and antimicrobial agent

Lauric arginate (LAE) has potent antimicrobial activity; however, it exhibits inadequate stability and antimicrobial efficacy due to interactions with anionic constituents. This study developed a novel LAE/hydroxypropyl-β-cyclodextrin inclusion complex (LAE/HP-β-CD IC), the structure of which was examined using various analytical techniques. The results showed that the non-polar tail of LAE likely penetrated the HP-β-CD cavity through its larger opening and exited through the narrower end, forming a partially included structure. The LAE/HP-β-CD IC effectively enhanced the thermal stability and emulsifying properties of LAE, extending its pH-stable range (1–9) and enabling stable storage for at least 35 d (4°C, pH 3–9). Moreover, it hindered the interactions between anionic components and LAE, enhancing its antimicrobial activity. The LAE/HP-β-CD IC significantly amplified the inhibition zone against Staphylococcus aureus from 15.54 to 31.64 mm and reduced the minimum inhibitory concentration of LAE against Escherichia coli from 0.038 to 0.020 mg/mL. This LAE/HP-β-CD IC is a promising novel emulsifying antimicrobial agent that could expand the application of LAE.