The Molecular Structure in Surface Films of Unsaturated 1-Monoglycerides on Water as Related to Three-Dimensional States¹

Abstract

The relationship of the molecular structure in monolayers of unsaturated 1-monoglycerides to three-dimensional states is discussed. Monolayers of cfs-monoglycerides were in the expanded state under all the conditions studied and extremely stable. The physical properties of the monolayers in this state resemble in certain respects the physical properties of three-dimensional liquids. An expanded monolayer of 1-monoelaidin was transformed under pressure to a condensed state with a limiting area of 24 Á.2 3. This area was in close agreement with the cross-sectional area calculated for a hypothetical liquid crystal from density and X-ray data. The correlation indicates that the orientation of the molecules in the condensed monolayer of 1-monoelaidin approximates the orientation in the anhydrous three-dimensional crystal.

Interactions of monolayers of unsaturated phosphocholines with ozone at the air-water interface

“…The unsaturated phospholipids studied were >99% phosphocholines; the major impurities were the positional isomers which according to the manufacturer were present at the 2-3% level. HPLC analysis using a 30 cm x 0.39 cm Nova-Pak Cis 4-um reversed phase column (Waters) and a methanolwater (97:3) (v/v)) mobile phase containing 40 mM choline chloride at a flow rate of 1 cm3 min-1 showed total detectable impurity levels to be <2% by area.…”

“…), which had been cleaned by soaking and washing first with methanol and then with chloroform in an ultrasonic bath for 30 min and then dried, were carefully and repeatedly run along the water surface to adsorb the phospholipids. The isolated monolayers from approximately 40 experiments were pooled to obtain sufficient material for analysis. The products which adhered to the Teflon tapes were recovered by extracting the tapes with ~300 mL of chloroform; the overall recovery of the surface products was estimated to be -50%' on the basis of experiments using unreacted phospholipid.…”

PC-SAFT Modeling of Phase Equilibria Relevant for Lipid-Based Drug Delivery Systems

“…The pure-component parameters of MG8 0 , MG10 0 , and DG10 0 10 0 were fitted to vapor pressures from the literature as well as to density data from the literature and from Table . The density of the glycerides increases with increasing carbon-chain length.…”

“…Vapor pressures of MG12 0 and densities of MG12 0 were determined in this work. All other data were taken from the literature. , Solid lines were calculated using PC-SAFT with parameters from Table .…”

“…All other data were taken from the literature. 33,34 Solid lines were calculated using PC-SAFT with parameters from Table 12. pure MG8 0 , the second one describes Capmul MCM as a mixture of 90 wt % MG8 0 and 10 wt % DG10 0 10 0 .…”