Phase behavior and hydrated solid structure in lysophospholipid/long-chain alcohol/water system and effect of cholesterol addition.
Phase behavior in lysophospholipid/long-chain alcohol/water system at 80°C was investigated using hexanol and oleyl alcohol as the long-chain alcohol. Similarly to hydrophilic surfactant, a micellar phase in a lysophospholipid/water system transitioned to a lamellar liquid-crystalline phase by the addition of long-chain alcohol. In the oleyl alcohol system the lamellar liquid-crystalline phase was observed in wider region compared to the hexanol system. The effect of cholesterol addition on the phase behavior was also studied. The region of liquid-crystalline phase and (reverse micellar + liquid-crystalline + water) phase shifted towards higher lysophospholipid concentrations. The structure of hydrated solid as well as the transition between lamellar liquid-crystalline phase and hydrated solid was analyzed by X-ray scattering measurement and differential scanning calorimetry measurement. It was revealed that the hydrated solid was α-type crystals with lamellar structure. The hydrated solid (gel)-liquid crystal transition temperature gradually decreased with increasing oleyl alcohol concentration and the decrement was enhanced by the addition of cholesterol.
Research Development Division, KOSE Corporation, Tokyo, Japan. y-konno@kose.co.jp
Yoshikazu
Y
Konno
Noboru
N
Naito
Akio
A
Yoshimura
Kenji
K
Aramaki
D002152:Calorimetry, Differential Scanning; D002784:Cholesterol; D003460:Crystallization; D005233:Fatty Alcohols; D000441:Hexanols; D008051:Lipid Bilayers; D008246:Lysophospholipids; D008823:Micelles; D013696:Temperature; D014867:Water; D014961:X-Ray Diffraction
D005233:Fatty Alcohols; D000441:Hexanols; D008051:Lipid Bilayers; D008246:Lysophospholipids; D008823:Micelles; D014867:Water; C010268:oleyl alcohol; D002784:Cholesterol