A near infrared assay for lipolysis in lecithin-stabilised water-in-oil microemulsions

Microemulsification of Triglyceride Sebum and the Role of Interfacial Structure on Bicontinuous Phase Behavior

“…At lower surfactant concentrations, the very slow phase separation kinetics severely hampered efforts to map out the three-phase region. The efficiency of amphiphilic surfactant is usually expressed in terms of the minimum weight fraction of surfactant necessary to form a one-phase microemulsion containing equal amounts of water and oil . From Figure , we see that less than 20% surfactant is necessary to microemulsify triolein and water at a 1:1 weight ratio.…”

“…However, the microemulsification of molecularly large and partially amphiphilic oils such as triglycerides is notoriously difficult. Careful studies of the phase behavior of triglycerides with nonionic surfactants have consistently shown the existence of persistent asymmetric lamellar phases that solubilize very little oil. − While patents and reports abound that claim the microemulsification of triglycerides using a wide variety of surfactants, − there have been no reports of triglyceride microemulsions that exhibit the characteristic patterns of nonionic surfactant phase behavior 27 and which allow precise control of the phase behavior and microstructure ranging from water-continuous to bicontinuous to oil-continuous. Minana-Perez et al have previously reported the use of alkyl sulfates with oxypropylene groups inserted between the sulfate headgroup and the alkyl tail for forming efficient microemulsions of the bicontinuous type.…”