RESUMEN
Lu4O(OH)9I·3H2O is a new member of the anion exchangeable lanthanide hydroxyanion family of materials which has been synthesised hydrothermally. Its structure comprises positively charged [Lu4O(OH)9(H2O)3](+) layers with exchangeable charge balancing iodide anions located in the interlayer gallery. It has been found to undergo facile anion exchange reactions with dicarboxylate anions such as succinate and terephthalate at room temperature but reacts less readily with disulfonate anions such as 1,5- and 2,6-naphthalenedisulfonate under the same conditions. At reaction temperatures above 200 °C the cationic inorganic framework Lu3O(OH)6I·2H2O forms instead of the layered phase.
RESUMEN
Enhancing the activity of existing antimicrobial agents may help to address the emergence of resistant bacteria. Nanoparticles of antimicrobial agents have previously been shown to provide potential activity enhancements and here we report a high-throughput nanoprecipitation approach to identify viable nanosuspensions of the antimicrobial compound triclosan. Through careful choice of the components of the nanoprecipitation, amorphous nanosuspensions were created, freeze-dried and redispersed in water with z-average diameters varying from 170-290 nm. Particle size was shown to be controlled by a series of factors including polymer/surfactant concentration and concentration of triclosan solution prior to nanoprecipitation. A ten-fold decrease (i.e. higher activity) in the Escherichia coli (E. coli) inhibitory concentration (IC50) of triclosan, compared to an aqueous control, was observed for nanoparticles prepared using Pluronic® F68 and the cationic surfactant Hyamine. This overall approach offers a rapid route for identifying viable nanosuspensions and enhancing the properties of commercially available biologically active compounds with poor water-solubility.