• Archives of Pharmacal Research
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• v.10 no.2
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• pp.75-79
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• 1987

Liposomes were studied as a drug delivery system. Multilamellar vesicles, small unilamellar vesicles and large unilamellar vesicles containing cytarabine were prepared using egg yolk lecithin and cholesterol. Large unilamellar vesicles showed the highest encapsulation efficiency of all and their encapsulation efficiency increased as the buffer volume decreased. Cholesterol increased the stability of liposomal drug products as drug carriers and reduced the permeability of drug across the liposomal membrane. The release rate of cytarabine increased with incubation temperature and decreased with cholesterol incorporation in liposomal membrane. The release mechanism of cytarabine from large unilamellar vesicles in vitro was chiefly due to simple diffusion across the liposomal membrane rather than liposomal rupture.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.2
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• pp.1-21
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• 1995

In this context, it should be mentioned that multilamellar vesicles can be prepared with the main compounds of the intercellular lipids, ceramides, cholesterol, cholesteryl ester, squalane, lecithin, wax ester by effect of the wetting. We investigated properties formation of MLV with use of the AHAsomes and Microfluidizer. The multilamellar vesicles are formed merely adding polyol and water phase, followed with the microfluidizer. Formation of a practically pure AHAsomes system, containing the active ingredients directly incorporated without need for preservatives. There were very good encapsulated properties of the active ingredients whether hydrophilic(malic acid, tartaric acid, lactic acid, allantoin, urea) and hydrophobic(vitamin-I acetate, vitamin-A palmitate). Optimum condition (ormatiom of MLV was passed three times in the microfluidizer, particle size of the vesicles should be within range 50-523nm (mean=163.5nm). As application, It was compared that horny layer of the sole of foots removal with the general OM emulsion and the AHAsomes cream. There was used for three months, those got recovery wrinkles about 151.8% and elasticity three times more the AHAsomes than O/W emulsions, It was confirmed with the Image Analyzer and the Cutometer.

• Journal of Pharmaceutical Investigation
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• v.29 no.4
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• pp.279-285
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• 1999

Retinoids in anti-wrinkle cosmetics are widely used for the treatment of the photoaging skin these days, but very unstable in the presence of water. Multilamellar liquid crystal vesicles consisted of $poly(oxyethylene)_{15}oleyl$ ether $(POE_{15}OE)$ or $poly(oxyethylene)_{15}stearyl$ ether $(POE_{15}SE)$, cetostearyl alcohol (CSA) and cholesterol or oils were prepared to increase the stability of retinyl acetate or retinyl palmitate. $POE_{15}SE-CSA-Water$ systems were more unstable than $POE_{15}SE-CSA-Water$ systems due to the bended structure of oleyl groups. For the modification of vesicles, cholesterol was added. The enthalpy values were decreased reaching to zero and the water permeability of systems was decreased, but the stabilizaton of retinyl acetate was not greatly improved. The stability of retinyl acetate may depend on its location in the structure. Various oils were added for further stabilization and isopropyl myristate was most effective. In practice, retinyl palmitate showed better stability in the same vesicle than retinyl acetate, and the improved vesicles could be used for the anti-wrinkle cosmetics

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.1
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• pp.40-59
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• 1996

Retinyl Palmitate, the skin normalzer, is useful to promote greater skin elasticity, to diminish lipid peroxidation and skin roughness following UV exposure, and promote a youthfull general skin appearance. We knew that the reduction of retinyl palmitate in W/O, W/S, O/W, MLV cream was caused by variable compound factors. Among the retinoids, we chose retinyl palmitate and studied the stability behavior of retinyl palmitate is liposomed. Furthermore, HPLC, CHROMA METERS, LASER SIGHT SCATTERING SYSTEM and FREEZE FRACTURE SCANNING ELECTROM MICROSCOPY was used to analyzing the stability and efficacy of UV and heat.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.1
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• pp.38-52
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• 1995

The liposomes have been developed in many drugs and cosmetics fields. In this context, it should be mentioned that MLV liposomes can be prepared standing with the main compounds of the intercellular lipids, cholesterol, palmitic acid, cholesteryl ester and lecithin, by swelling reaction. We report properties of the formation of MLV liposomes with use of the lipid base and Microfluidizer. MLV liposomes formed as multilamellar vesicles(MLV). The effect of the gelation of MLV liposomes have been on swelling reaction which have been mixed lipid with polyol and water phase at high temperature(90$\pm$5$^{\circ}C$). MLV liposomes have been prepared in incorporating alpha hydroxy acid ligrediens. Optimum condition of MLV liposomes were passed three times in the microfluidizer, particle size of the vesicles should be within 150-350nm and those confirmed by freeze-fracture electron microscopy.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.283-283
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• 1996

The hydrolyzed-lactose milk for the lactase-deficient subject is sweeter than whole milk, and some subjects dislike its taste. To overcome this shortcoming the dried liposomes containing ${\beta}$-galactosidase to digest lactose in milk after drinking were prepared and examined the possible application of this dried liposomes to the lactase-deficient subjects. To improve the stability of conventional liposome suspension, the dried liposomes in the presence of trehalose were prepared by the dehydration-rehydration vesicles method. Small unilamellar vesicles, prepared with egg phosphatidyl cholesterol, and cholesterol, were mixed with ${\beta}$-galactosidase solution and then ;up[jo;ozed. The freeze-dried liposome was rehydrated and centrifuged. The resultant multilamellar vesicles were mixed with trehalose(4g/g lipid) and then lyophilized to produce final dried liposome. Trehalose increased the entrapping efficiency of liposomes by 3 fo1d compared to the liposomes without trehalose (13% vs. 46%).

• Journal of the Korean Magnetic Resonance Society
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• v.13 no.1
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• pp.1-6
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• 2009

Syndecan-4 cytoplasmic domain was tested to confirm the interactions with the bilayer membrane using $^{31}P$ solid-state NMR measurements. Syndecan-4 was known as a coreceptor with integrins in the cell adhesion. The syndecan-4 V region is not understood of its functional roles and tested its ability of the interaction with multilamellar vesicles. The $^{31}P$ powder pattern was dramatically changed and showed isotropic peak which imply the bilayer membrane changed its topology to the micelle-like structure. Especially, phosphatidylcholine membrane was affected this effect more than phosphatidylethanolamine membrane.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.43-52
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• 1988

To elucidate the mechanism of action of local anesthetics, the effects of local anethetics on the microenvironment of the lipid bilayers of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine brain and dimyristoylphosphatidylcholine (DMPC) multilamellar liposomes were investigated employing the intermolecular excimer fluorescence technique and differential scanning calorimetry (DSC). The relative intensities of excimer and monomer fluorescence of pyrene are a simple linear function of the viscosity of a homologous series of solvents. The microviscosity(${\eta}$)of the hydrocarbon region of SPMV was measured by this method and the value was $57.3{\pm}5.3\;cP$ at $37^{\circ}C$. In the presence of lidocaine-HCl and procaine-HCl, the values decreased to $46.5{\pm}5.1\;cP$ and $54.7{\pm}4.8\;cP$, respectvely. The differential scanning thermograms of DMPC multilamellar liposomes showed that local anesthetics significantly lowered the phase transition temperature, broadened the thermogram peaks, and reduced the size of the cooperative unit. These results indicate that local anesthetics have significant fluidizing effects on biomembranes and perturbation of membrane lipids may produce some, but not all, of their pharmacological actions.

• Archives of Pharmacal Research
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• v.9 no.3
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• pp.119-125
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• 1986

Digitonin is a strong hemolysin and glycyrrhizin has protective activity against the deterring effect of other hemolytic saponins. The interaction of these saponins with liposomes was studied as a function of cholesterol in membrane. In the case of multilamellar vesicles, which act as ideal osmometers, digitonin distrupted the barrier function of liposomes composed of phosphatidyl choline, dicetyl phosphate and cholesterol, however, did not influence on cholesterol-lacking liposomes. Glycyrrhizin had similar effect on liposomes irrespective of cholesterol in membrane. In the test with large unilamellar vesicles, digitonin increased the lysis with increasing cholesterol content in membrane, but glycyrrhizin showed no detectable change in cholesterol-containing liposomes. These results suggest that incorporation of cholesterol into liposomes increases the susceptibility to digitonin, resulting in lysis of liposomes, and that the inhibitory effect of glycyrrhizin against other hemolytic saponins in cholesterol-independent.

• Journal of the Korean Chemical Society
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• v.67 no.2
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• pp.89-98
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• 2023

The cell membrane, also known as the biological membrane, surrounds every living cell. The main components of cell membranes are lipids and therefore called as lipid membranes. These membranes are mainly made up of a two-dimensional lipid bilayer along with integral and peripheral proteins. The complex nature of lipid membranes makes it difficult to study and hence artificial lipid membranes are prepared which mimic the original lipid membranes. These artificial lipid membranes are prepared from phospholipid vesicles (liposomes). The liposomes are formed when self-forming phospholipid bilayer comes in contact with water. Liposomes can be unilamellar or multilamellar vesicles which comprises of phospholipids that can be produced naturally or synthetically. The phospholipids are non-toxic, biodegradable and are readily produced on a large scale. These liposomes are mostly used in the drug delivery systems. This paper offers comprehensive literature with insights on developing basic understanding of lipid membranes from its structure, organization, and phase behavior to its potential use in biomedical applications. The progress in the field of artificial membrane models considering methods of preparation of liposomes for mimicking lipid membranes, interactions between the lipid membranes, and characterizing techniques such as UV-visible, FTIR, Calorimetry and X-ray diffraction are explained in a concise manner.