Preparation of Nonionic Vesicles Using the Supercritical Carbon Dioxide Reverse Phase Evaporation Method and Analysis of Their Solution Properties

Preparation and Properties of Nonionic Vesicles Prepared with Polyglycerol Fatty Acid Esters Using the Supercritical Carbon Dioxide Reverse Phase Evaporation Method

“…These findings indicate that two factors, i.e., high solubility of the PG ester-type nonionic surfactants in scCO 2 on addition of ethanol and choice of nonionic surfactants with an HLB value within the optimal HLB range, are required for the formation of niosomes by the scRPE method. These requirements for PG ester-type nonionic surfactants are similar to those for ethylene oxide-type nonionic surfactants, as reported in our previous study 19 . Table 2 Appearance, average particle sizes, and trapping efficiency for PG ester-type nonionic surfactant suspensions using the scRPE method.…”

“…Fluorescence polarization P was calculated using the following equation. 3 Results and discussion 3.1 Solubility of nonionic surfactants in scCO 2 and dependence on ethanol addition In our previous study 19 , we found that, to form niosomes using the scRPE method, the nonionic surfactants must be completely dissolved in scCO 2 , and the hydrophilic-lipophilic balance HLB of the surfactants must be in the range of 9.5 to 9.9. All nonionic surfactants used in the present study were poorly soluble in scCO 2 at 60 without the use of co-solvents.…”

“…We previously reported 19 that the optimum HLB values for niosome formation with nonionic surfactants range from 9.5 to 9.9. For DG2S and DG2IS, whose HLB values are in or close to this range, niosomes were formed using the scRPE method.…”

“…Recently, we reported a new, environmentally friendly method, the supercritical carbon dioxide reverse phase evaporation method scRPE method , for the preparation of liposomes or niosomes in a single step using supercritical CO 2 scCO 2 16, 17 . However, niosome formation by the scRPE method has been demonstrated only for nonionic surfactants with polyoxyethylene as the hydrophilic group 18,19 . In pharmaceuticals, cosmetics, and food products, consumers prefer to use products made from safer materials, especially plant-derived materials.…”

Properties and Applications of Highly Stable Vesicles Formed by Nanoarchitectonics of Amphiphilic Molecules

“…dioxide reverse phase evaporation method As with liposomes, several methods of preparing niosomes utilize organic solvents such as chloroform, and concerns have been raised about the biological and environmental effects of these residues. In contrast, we focused on supercritical carbon dioxide (sc-CO 2 ) as an alternative solvent and reported the preparation of liposomes 25−27) and niosomes 28,29) by sc-CO 2 reverse phase evaporation (sc-CO 2 -RPE) method using sc-CO 2 as a solvent (Fig. 6) .…”