Effects of Oleic Acid and Phospholipids on the Formation of Lecithin Organogel and Microemulsion

Abstract

The formation of organogels and microemulsions of lecithin in the presence of a biocompatible cosurfactant, oleic acid, was studied. Low content of oleic acid ([oleic acid]/[lecithin] < 0.1) in the lecithin–oleic acid–dodecane–water system leads to an expansion of the region of existence and to a decrease in the viscosity of lecithin organogels. At high contents of oleic acid ([oleic acid]/[lecithin] > 0.6), low‐viscosity microemulsion exists in the system. Phosphatidylethanolamine, lysophosphatidylcholine, and other phospholipids that are present as impurities in the commercial samples of soybean lecithin can act as cosurfactants. For the first time, the formation of lecithin organogels in the systems containing commercial samples of soybean lecithin with phosphatidylcholine concentrations of 69.3 wt% (Lipoid S75) and 52.9 wt% (Lipoid S45) and saturated aliphatic hydrocarbons is demonstrated. The gelation is observed at T =25 °C in octane, decane, dodecane, and hexadecane for Lipoid S75 and in dodecane and hexadecane for Lipoid S45. A decrease in the degree of purification of lecithin leads to an expansion of the regions of existence of the organogels and to a reduction of their viscosity.

Lecithins: A comprehensive review of their properties and their use in formulating microemulsions

“…In contrast, medium‐chain fatty acids shrank the isotropic region in phase diagrams. Murashova et al (2018) used oleic acid (18:1) as a co‐surfactant in lecithin‐based microemulsions. They reported an expansion of the one‐phase isotropic region at low content of oleic acid ([oleic acid]/[lecithin] < 0.1).…”

“…These inverted micelles grow mono-dimensionally into elongated flexible and tubular giant micelles upon adding a specific amount of water. The water molecules create hydrogen bonds with phosphate groups and induce a gel network or jelly-like state (Murashova et al, 2018). On the other hand, the hydrogels are formed from a water-continuous microemulsion added with a hydro-gelling agent (i.e., gelatin, carbomer, carbopol, and carrageenan) (Elnaggar et al, 2014).…”

“…phase diagrams Murashova et al (2018). used oleic acid (18:1) as a co-surfactant in lecithin-based microemulsions.…”

Liquid Crystals as Drug Carriers in “Lecithin – Vegetable Oil – Essential Oil – Water” Systems

“…Лецитин -распространенный ПАВ природного происхождения, основной липидный компонент клеточных мембран. Кроме хорошо известных липосом, в качестве носителей для адресной доставки лекарственных веществ предлагаются такие наноструктуры лецитина, как лецитиновые органогели, построенные из обратных цилиндрических мицелл лецитина, обратные микроэмульсии в системах, содержащих лецитин и олеиновую кислоту, и лиотропные жидкие кристаллы в системах лецитин -масло -вода [3][4][5].…”

Микроэмульсии И Лиотропные Жидкие Кристаллы Лецитина Как Системы Для Трансдермальной Доставки Лекарственных Веществ

“…Поэтому для разработки микроэмульсионных систем на основе лецитина необходимо подбирать нетоксичное и биосовместимое соПАВ. В качестве соПАВ, способствующих образованию микроэмульсии лецитина, могут выступать олеиновая кислота или фосфолипиды, содержащиеся в виде примесей в коммерческих образцах соевого лецитина [16].…”