Amphiphile association structures

The amphiphile association behavior of Aerosol OT (sodium di-w-ethylhexylsulfoccinate) and p-xylene in combination with mixtures of different ratios of glycerol/water systems was studied and compared to that in the corresponding water and glycerol systems. The presence of glycerol strongly destabilized the inverse hexagonal liquid crystal phase observed in the aqueous system. The glycerol showed more ability to penetrate into the amphiphile bilayer than water in the lamellar liquid crystal phase. The influences of water and glycerol on the organization of amphiphile in the lamellar liquid crystal phase are of the same order. The gross diffusion coefficient of 1% 2,4-diamino-6-piperidinopyrimidine-3-oxide in a liquid crystalline vehicle (phosphatidyl choline 65%, propylene glycol 30%, and water 5% by weight) in contact with a model sebum was determined by a direct analysis. Concentration profiles of 2,4-diamino-6- piperidinopyrimidine-3-oxide as a function of distance from the initial dividing surface for the vehicle-vehicle, model sebum-model sebum, and vehicle-model sebum systems were determined --Abstract, page ii