title: Synergistic cosolubilization of omega-3 fatty acid esters and CoQ10 in dilutable microemulsions.
abstract: Water-dilutable microemulsions were prepared and loaded with two types of omega-3 fatty acid esters (omega-3 ethyl esters, OEE; and omega-3 triacylglycerides, OTG), each separately and together with ubiquinone (CoQ(10)). The microemulsions showed high and synergistic loading capabilities. The linear fatty acid ester (OEE) solubilization capacity was greater than that of the bulky and robust OTG. The location of the guest molecules within the microemulsions at any dilution point were determined by electrical conductivity, viscosity, DSC, SAXS, cryo-TEM, SD-NMR, and DLS. We found that OEE molecules pack well within the surfactant tails to form reverse micelles that gradually, upon water dilution, invert into bicontinuous phase and finally into O/W droplets. The CoQ(10) increases the stabilization and solubilization of the omega-3 fatty acid esters because it functions as a kosmotropic agent in the micellar system. The hydrophobic and bulky OTG molecule strongly interferes with the tail packing and spaces them significantly - mainly in the low and medium range water dilutions. When added to the micellar system, CoQ(10) forms some reverse hexagonal mesophases. The inversion into direct micelles is more difficult in comparison to the OEE system and requires additional water dilution. The OTG with or without CoQ(10) destabilizes the structures and decreases the solubilization capacity since it acts as a chaotropic agent to the micellar system and as a kosmotropic agent to hexagonal packing. These results explain the differences in the behavior of these molecules with vehicles that solubilize them in aqueous phases. Temperature disorders the bicontinuous structures and reduces the supersaturation of the system containing OEE with CoQ(10); as a result CoQ(10) crystallization is retarded.
authors: The Ratner Chair of Chemistry, Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel.
authors: Rivka
authors: R
authors: Deutch-Kolevzon
authors: Abraham
authors: A
authors: Aserin
authors: Nissim
authors: N
authors: Garti
mesh_terms: D002152:Calorimetry, Differential Scanning; D004553:Electric Conductivity; D004655:Emulsions / Q000737:chemistry*; D015525:Fatty Acids, Omega-3 / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D011092:Polyethylene Glycols / Q000737:chemistry; D053838:Scattering, Small Angle; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000737:chemistry; D014783:Viscosity; D014961:X-Ray Diffraction
chemical_list: D004655:Emulsions; D015525:Fatty Acids, Omega-3; D008823:Micelles; D013501:Surface-Active Agents; D014451:Ubiquinone; D011092:Polyethylene Glycols; C024989:coenzyme Q10