Improving the aqueous solubility and antibacterial activity of triclosan using re-dispersible emulsion powder stabilized with gold nanoparticles†

Triclosan (TCS) is used as an antibacterial agent in various products. One of the major issues associated with TCS is its limited solubility in aqueous media, which can reduce its effectiveness against bacteria. In this study, we enhanced the aqueous solubility and antibacterial activity of TCS by using a re-dispersible emulsion powder stabilized with gold nanoparticles (GNPs). The developed formulation (TCS/PEG-B/GNPs) demonstrated the ability to dissolve in aqueous media and provided good stability. An antibacterial investigation was conducted using drug-resistant bacterial strains, Escherichia coli (E. coli) BAA-1161 and methicillin-resistant Staphylococcus aureus (MRSA), as model bacteria. The results showed that TCS/PEG-B/GNPs had the highest antibacterial activity. The MRSA strain demonstrated greater susceptibility to TCS (both TCS alone and TCS in the formulation) than E. coli BAA-1161. The cytotoxicity assay was also conducted in THP-1 cells and it was found that the viability of THP-1 cells treated with a 5× dilution of TCS/PEG-B/GNPs was higher than 80%. Altogether, our study proposes a novel approach to overcome the solubility concerns of TCS. These results demonstrated an increase in TCS's solubility and efficacy, which holds great promise for future applications.