• 한국응용과학기술학회지
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• 제25권1호
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• pp.48-51
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• 2008

Dipalmitoyl phosphatidyl choline and p-nitrophenyl palmitate were directly sonicated in acidic water for 6 minutes to give clear stock solutions. The catalytic hydrolysis of p-nitrophenyl palmitate was studied at $30-50^{\circ}C$ in the presence of unilamellar vesicle and mixture of unilamellar and multilamellar aggregates. The difference of reaction rate between unilamellar and multilamellar was observed. The rate of unilamellar reaction compared to the rate of mixture reaction showed more catalytic effect. The phase transition temperature of vesicle was measured at $37-44^{\circ}C$.

• Archives of Pharmacal Research
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• 제7권1호
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• pp.17-22
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• 1984

Effects of total ginseng saponin, 20-S-protopanaxadiol saponin, 20-S-protopanaxatriol saponin and playcodon saponin on the osmotic behavior of liposomes were investigated by optical measurement. These saponins showed different activities on liposomal membrane, and cholesterol in liposomes was an important factor to this variation of saponin activities.

• Archives of Pharmacal Research
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• 제10권2호
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• pp.94-99
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• 1987

By using the former equation (8), we modified the equation which can show the dissimilar osmotic behavior of liposome with composition change. The slope of the new equation was presented as the ratio of osmotically active volume (V$_{act}$= ) to the total volume (V$_{totel}$= $_{acl}$+ V$_{dead}$ ; V$_{dead}$ is osmotically inactive volume) of loposomes, we defined is as a Z-value, which can elucidate the dissimilarity of the osmotic activity of multilamellar liposomes with the change of phospholipid composition and the differences of physicochemical properties of liposomes. Z-value was applied for studying the physico-chemical properties of liposomal membrane. The factor that affects on the Z-value was not the lipid concentration of liposome stock dispersion but the lipid composition of liposomal membrane. As the content of dicetylphosphate, the negative charged phospholipid, was increased, the osmotic activity, represented by Z-value, of multilamellar liposome was decreased. Using the hypertonic conditions (shrinking region), Z-value steadily increased and reached a maximum at 10 mole percent cholesterol with increasing the cholesterol content.

• 한국자기공명학회논문지
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• 제13권1호
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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.

• Archives of Pharmacal Research
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• 제10권2호
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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.

• 대한화장품학회지
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• 제21권2호
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• pp.1-21
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• 1995

본 연구는 세포 간지질이 주성분인 세라마이즈, 콜레스테롤, 콜레스테롤 에스텔, 스쿠알란, 레시친, 왁스 지방산을 팽윤 반응에 의하여 다중라멜라 소구체를 제조하였다. AHAsomes과 마이크로 플루다이저를 사용하여 MLV 형성에 대한 특성을 조사 하였다. 다중라멜라 소구체는 Polyol과 수상을 서서히 첨가하고, 마이크로 플루다이저를 사용함에 의해 자연스럽게 형성된다. 실제적으로 이 AHAsomes system의 형성은 방부제가 필요하지 않고, 활성 미용 성분을 침투시켰다. 친수성 활성 성분인 말릭산, 타타릭산, 락틱산, 알란토인, 우레아 그리고 소수성 미용 성분인 비타민-E 아세테이트, 비타민-A 팔미테이트를 캡슐화시켰다. MLV형성 조건은 마이크로플루다이저에 3회 통과하였으며, 베지클의 입자크기의 범위는 50-523nm이었다. 응용으로, 일반적인 O/W 에멀젼과 AHAsomes 크림을 사용하여 발바닥의 각질제거 효과를 비교하였다. 3개월동안 사용하여 주름은 15.8%, 피부 탄력은 3배정도 회복되었다. 이것을 Image Analyzer와 Cutometer로 확인하였다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.286-286
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• 1996

In order to elucidate the mechanism of action of transdermal absorption-enhancing compounds, i.e., pyrrolidone derivatives (2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1,5-dimethyl-pyrrolidone and 5-methyl-2-pyrrolidone), multilamellar liposome was prepared from the simulated stratum corneum lipid and employed as a model system for the barrier function of the stratum corneum. The liposomal membrane of the stratum corneum lipid liposome (SCLL) behaves as an osmometer and has an excellent barrier function. In addition, its phase transition temperatures are similar to those of human stratum corneum intercellular lipid region. Therefore, SCLL seems to be a useful skin model. To estimate the barrier function of SCLL, the osmotic behavior of SCLL was measured in the presence of pyrrolidone derivatives and the effect on the phase transition temperature of SCLL was also investigated using differential calorimetry. Above a certain concentration (MLAC), enhances perturb the barrier function of the liposome. The relationship between MLACs and the partition coefficient of the pyrrolidone derivatives was observed; the greater the partition coefficients, the smaller the MLAC. This suggests that the more hydrophobic enhancers penetrate into the lipid layer more easily and reduce the barrier function of membrane more effectively. The results of differential scanning thermograms of the SCLL suggest that the pyrrolidone derivatives had incorporated into the lipid layer in the liposome and increased the fluidity of the lipid layer in the liposome. Such activity might have some correlation with the transdermal absorption-enhancing activity these compounds.

• 대한화장품학회지
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• 제22권1호
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• pp.40-59
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• 1996

Retinol은 열과 빛에 쉽게 산화되기 때문에 그 유도체인 Retinyl Palmitate를 사용하고 있으나 이것 또한 안정성이 우려되어 많은 양을 사용하지 못하고 있다. 본 연구에서는 Retinyl Palmitate 5% 와 Tocopgeryl Acetate 10%를 함유한 W/O, W/S, O/W, MLV Type의 크림에서 열적 안정성 및 UV 안정성을 CHROMA METERS로 측정하였으며, $25^{\circ}C$, $45^{\circ}C$에서 RP의 함량을 HPLC로 정량 분석하였다. 또한 RP가 열, 빛 등에 의해서 어떤 물질로 변화하였는지를 측정하였으며, 변화된 물질의 독성에 대한 연구를 하였다. 각각의 크림 TYPE 마다 입자 SIZE를 측정했으며, DNA와 CHROMA METERS를 사용하여 CELLULAR RENEWAL을 측정하였다.

• Journal of Pharmaceutical Investigation
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• 제29권4호
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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

• 대한화장품학회지
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• 제21권1호
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• pp.38-52
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• 1995

Liposome은 의약과 화장품 분야에서 많은 발전을 하였다. 본 연구에서는 세포 간지질의 주요 성분인 cholesterol, palmitic acid, cholesterol ester와 lecithin을 사용하여 swelling반응에 의해 MLV liposome을 제조 하였다. 지질베이스와 마이크로플루다이저를 사용하여 MLV liposome 형성에 대한 특성들을 연구 하였다. MLV liposome은 multilamellar vesicle로서 형성되었다. MLV liposome의 gelation효과는 고온(90$\pm$5도씨)에서 polyol과 water phase에 지질을 혼합한 것에 스웰링 반응을 하였다. MLV liposome에 alpha hydroxy acid 성분들을 투입 제조하였다. MLV liposome의 최적 조건은 마이크로플루다이저에 3회 통과하였으며 vesicle의 입자크기는 150-350nm범위이고 이것을 freeze-fracture electron microscopy로 확인 하였다.