• Journal of Pharmaceutical Investigation
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• 제27권4호
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• pp.287-293
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• 1997

To make a stable o/w emulsion, the effects of egg lecithin as an emulsifier and polyvinylpyrrolidone (PVP) as an auxiliary emulsifier on the physical stability of emulsion were investigated. The oil-in-water emulsion system was manufactured by microfluidizer and evaluated the physical stability. Average particle size and size distribution of emulsion was measured by dynamic light scattering analyzer and interfacial tension was measured. From the interfacial tension tested, critical micelle concentration of the egg lecithin was 0.1 %w/v and optimal concentration for the preparation of emulsion was 1.0 %w/v. The mean particle size was about $0.2\;{\mu}m$ which was suitable for injections. The short-term accelerated stability studies were conducted by centrifugation, freeze-thaw method and shaking of the emulsion samples. The addition of PVP was caused the reduction in the particle size and improved the physical stability of emulsion. These results suggested that a mixed interfacial film comprising the egg lecithin and PVP was formed at the o/w interface and it was effective in preventing phase separation under thermic or mechanical stress. We used antineoplaston A10 (A10) as a model drug which is peptide and amino acid derivative having a action to the living organism against the development of neoplastic growth by a nonimmunological progress. It has a poor solubility in water and there may be a difficulty in formulation of A10. Emulsion formulation study about A10 was performed. Solubility of A10 in emulsion was about five times as high as that in water. From the results of solubility and partition coefficient, almost A10 molecules in o/w emulsion exist in the interface between oil and water.

• Preventive Nutrition and Food Science
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• 제3권2호
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• pp.133-142
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• 1998

Effects of protein heat treatment and surfactant additionoo the orthokindetic stability of $\beta$-lactoglobulin-stabilized emulsions have been investigated under turbulent flow conditions. In studies on protein-stabilized emulsions, samples which had been subjected to heat treatment(i.e. the protein solution orthe emulsion) have been found to be more prone to orthokinetic coalescene than the untreated ones. The emulsions stabilized with protein heated above the denaturation temperature(i.e. 7$0^{\circ}C$) showed the bigger initial average droplet size, which resulted in an increased orthokinetic coalescenece rate. The storage of the protein-stabilized emulsion at high temperature prior to the shearing experiment also made the emulsion less stable in the shear field. Interestingly. the addition of DATEM has been found to produce a substantial increase in orthokinetic stability of the heat-denatured protein-stabilized emulsion system, although Tween 20 is the opposite case.

• Journal of Pharmaceutical Investigation
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• 제31권4호
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• pp.241-256
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• 2001

Alginate microspheres, containing fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) or green fluorescent protein (GFP) were prepared and used as a model drug to develop the oral vaccine delivery system. The alginate microspheres were coated with poly-L-lysine or chitosan. Two methods, w/o-emulsion and spray, were used to prepare alginate microspheres. To optimize preparation conditions, effects of several factors on the particle size and particle morphology of microsphere, and loading efficiency of model antigen were investigated. In both preparation methods, the particle size and the loading efficiency were enhanced when the concentration of sodium alginate increased. In the w/o-emulsion preparation method, as the concentration of Span 80 was increased from 0.5% to 2%, the particle size was decreased, but the loading efficiency was increased. The higher the emulsification speed was, the smaller the particle size and loading efficiency were. The concentration of calcium chloride did not show any effect on the particle size and loading efficiency. In the spray preparation method, the particle size was increased as the nozzle pressure $(from\;1\;kgf/m^2\;to\;3\;kgf/m^2)$ and spray rate was raised. Increasing calcium chloride concentration (<7%) decreased the particle size, in contrast to no effect of calcium chloride concentration on the w/o-emulsion preparation method. Alginate microspheres prepared by two methods were different in the particle size and loading efficiency, the particle size of microspheres prepared by the spray method was about $2-6\;{\mu}m$, larger than that prepared by the w/o emulsion method $(about\;2{\mu}m)$, and the loading efficiency was also higher with spray method. Furthermore, drying process for the microspheres prepared by the spray was simpler and easier, compared with the w/o emulsion preparation. Therefore, the spray method was chosen to prepare alginate microspheres for further experiments. Release pattern of FITC-BSA in alginate microspheres was evaluated in simulated intestinal fluid and PBS (phosphate buffered saline). Dissolution rate of FITC-BSA from alginate/chitosan microsphere was lower than that from alginate microsphere and alginate/poly-L-lysine microsphere. By confocal laser scanning microscope, it was revealed that alginate/FITC-poly-L-lysine microspheres were present in close apposition epithelium of the Peyer's patches of rabbits following inoculation into lumen of intestine, which proved that microspheres could be taken up by Peyer's patch. In conclusion, it is suggested that alginate microsphere prepared by spray method, showing a particle size of & $10\;{\mu}m$ and a high loading efficiency, can be used as a model drug for the development of oral vaccine delivery system.

• 자원환경지질
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• 제46권1호
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• pp.51-61
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• 2013

최근 나노기술을 이용한 석유증진회수기술은 미국을 중심으로 활발한 연구가 진행되고 있다. 지금까지의 연구에서는 주로 다공성 매체 내 나노입자의 유동특성이나 나노 에멀젼 자체의 안정성 평가에만 중점을 두었으며, 다공성 매체 내 나노 에멀젼의 유동시 중요한 역할을 하는 나노 에멀젼과 공극의 크기 효과는 분석하지 않았다. 이 연구에서는 석유증진회수기술에 적용 가능한 나노기반의 에멀젼을 제조하였으며, 그 특성을 분석하였다. 또한 다공성 매체 내 나노 에멀젼의 유동특성을 파악하기 위해 필터링 시험을 통해 나노 에멀젼의 크기효과를 분석하였다. 연구결과 나노 에멀젼의 제조시 SCA(Silane Coupling Agent)나 PVA(poly Vinyl Aclohol)를 첨가하여 에멀젼을 제조할 때 안정성이 개선되며, 물에 비해 데칸의 비율이 높을수록 점성도가 높아지고, 액적크기가 증가하는 것을 확인하였다. 대기압조건하에서 수행한 필터링 시험에서는 분리된 물이 주로 통과하고 액적은 통과하지 못하는 것이 확인되었다. 이는 액적의 유동력이 필터에 작용하는 모세관압을 극복하지 못하였기 때문에 나타난 현상이다. 흡입압력을 작용한 필터링시험에서는 $60{\mu}m$ 크기 이상의 필터에서는 대부분 액적이 통과 하였으나, $45{\mu}m$ 이하의 필터에서는 통과비율이 급격히 저하되는 것을 확인하였다. 이러한 현상은 필터 공극 통과시 강한 전단응력에 의해 액적이 변형되거나 파괴되어 공극을 막기 때문에 나타나는 현상으로 보인다. 이 연구에서 밝혀진 기본적인 나노 에멀젼의 특성 및 필터링 시험 결과는 향후 안정적인 나노 에멀젼 제조나, 다공성 매체 내 잔류오일 회수연구에 중요한 역할을 할 수 있을 것이다.

• 한국식품영양과학회지
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• 제30권2호
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• pp.204-209
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• 2001

The effects of size distribution of oil particles on the emulsion stability of mayonnaise were studied as follows; The stability of mayonnaise has concerned closely with the viscosity and the size distribution of oil particles. Mostly, if the viscosity was increased, the stability was improved, and the distribution of oil particles was uniform and the less the variation, the more the stability. 75% of oil concentration of sample showed the highest viscosity, also the size of sample was the most uniform, compared to other concentration. Mayonnaise prepared with whole egg was unstable, and the size of oil particles was double larger than the case prepared with only the yolk. Addition of xanthan gum increased, the viscosity and the stability by centrifuge so that the more stable mayonnaise could be prepared. The result of using log-normal density function by Heldmann represented that the normal size of sample adding 0.6%-soluble starch and sample N in non-adding control was increased, while those of sample adding xanthan gum and soluble starch at the same time didn't change.

• Membrane and Water Treatment
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• 제4권1호
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• pp.11-25
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• 2013

Emulsion liquid membrane (ELM) process suffers from emulsion instability problem. So far, emulsion produced by mechanical methods such as stirrer and homogenizer has big size and high emulsion breakage. This paper discussed the application of emulsion produced by sonicator to extract cadmium in a batch ELM system. The emulsions consist of N,N-Dioctyl-1-octanamine (trioctylamine/TOA), nitrogen trihydride (ammonia/NH4OH), sorbitan monooleate (Span 80), and kerosene as carrier, stripping solution, emulsifying agent, and organic diluent, respectively. Effects of comprehensive parameters on extraction efficiency of Cd(II) such as emulsification time, extraction time, stirring speed, surfactant concentration, initial feed phase concentration, carrier concentration, volume ratio of the emulsion to feed phase, and pH of initial feed phase were evaluated. The results showed that extraction efficiencies of Cd(II) greater than 98% could be obtained under the following conditions: 15 minutes of emulsification time, 4 wt.% of Span 80 concentration, 4 wt.% of TOA concentration, 15 minutes of extraction time, 250 rpm of stirring speed, 100 ppm of initial feed concentration, volume ratio of emulsion to feed phase of 1:5, and initial feed pH of 1.53.

• 대한화장품학회지
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• 제35권3호
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• pp.179-191
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• 2009

본 연구에서는 poly(oxyethylene) hydrogenated castor oils (HCOs)/오일/에탄올/물로 이루어진 에멀젼에 대한 에탄올의 영향을 연구하였다. 에멀젼은 고에너지법인 균질기(homogenizer)를 병합하여 제조하였다. 에멀젼에 대한 에탄올의 영향을 평가하기 위해 입자 크기와 입자 분포 등의 물리적 특성을 측정하였으며 다른 성분의 조성은 같도록 하였다. HCO-20의 경우 에멀젼의 크기가 마이크로미터 크기에서 에탄올이 증가할수록 입자의 크기가 감소하는 것을 확인하였다. HCO-30의 경우 계면활성제 농도 4.00 %에서 입자 크기가 나노미터 크기로 나타났으며, 에탄올의 농도가 4.25 % 일 때 조성 1에서 입자 크기가 $128.15{\pm}1.06nm$이고 조성 2에서는 $136.10{\pm}0.99nm$로 가장 안정한 나노에멀젼이 생성되었다. 마찬가지로 HCO-40은 계면활성제 농도 4.00 %에서 입자가 나노미터 크기로 나타났으며, 에탄올이 4.50%일 때 조성 1에서 입자 크기가 $115.85{\pm}0.78nm$이고 조성 2는 $121.15{\pm}0.35nm$로 안정한 나노에멀젼이 생성되었다. HCO-60의 경우에서는 계면활성제 농도 4.00 %, 에탄올 농도 2.25 %에서 에멀젼의 크기가 $262.35{\pm}0.64nm$인 안정한 나노에멀젼이 생성되었다. 마이크로 크기의 에멀젼에서는 에탄올의 함량이 증가할수록 입자의 크기가 감소하는 것을 알 수 있었고, 나노에멀젼에서는 에탄올의 특정 농도에서 최저값을 나타냄을 확인하였다. 나노에멀젼의 불안정화 과정은 Ostwald ripening에 의한 것으로 보여진다. 계면활성제 종류에 따른 에멀젼에 대한 에탄올의 영향을 연구함으로써 안정한 에멀젼을 만들기 위한 에탄올의 함량을 계산할 수 있을 것으로 사료된다.

• 한국세라믹학회지
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• 제24권6호
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• pp.593-601
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• 1987

A thermodynamic model to predict the stability of the water-in-oil type emulsion and the size of the droplets in stable emulsions was developed. Using this model, the effects of various factors government the droplet size in the metal salt solution-kerosene-span 80 system for the preparation of Al2O3-ZrO2 composite powders were investigated. It was shown that the given emulsion systems were thermodynamically unstable in every case but could be kinetically meta stable. When radius ofthe droplet was below nm, the increase in entropy change due to the configurational contribution of small droplets dominated the total free energy change for emulsification. The optimum conditions under which smaller deoplet was obtained were proposed and the validity of the model was proved with diameters of the droplet and composite powders experimentally determined.

• 멤브레인
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• 제20권2호
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• pp.87-96
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• 2010

세공 크기가 2.6 ${\mu}m$인 SPG (Shirasu porous glass) 막이 설치된 실험실 규모의 막유화 장치를 사용하여 막유화 에멀젼-겔 공정의 변수 조절을 통해 구형상의 실리카 입자를 제조하였다. 막유화 에멀젼-겔 공정의 변수로는 분산상 압력, 연속상 내 안정제 및 유화제의 농도, $H_2O$/TEOS 비율 및 연속상에 대한 분산상의 비율로 설정하고, 이들 변수가 제조된 실리카 입자의 크기와 분포에 미치는 영향을 검토하였다. 막유화의 공정변수들 중에서 분산상 압력과 연속상에 대한 분산상의 비가 증가할수록 실리카 입자의 크기가 증가하였다. 반면 안정제 및 유화제의 농도, $H_2O$/TEOS 비가 증가할수록 입자의 크기가 감소하였다. 막유화 에멀젼-겔 공정변수의 조절을 통해 최종적으로 평균 입자 크기가 3 ${\mu}m$인 비교적 입도분포가 균일한 구형상의 실리카 입자 제조가 가능하였다.

• Food Science and Biotechnology
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• 제17권2호
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• pp.324-329
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• 2008

The effect of ultra-high pressure homogenization on the emulsifying properties of whey protein was investigated in a model emulsion made with whey protein isolate and soya oil under various pH. The emulsifying properties, the average diameter of the oil droplets ($d_{vs}$), and the protein load, were measured for each emulsion produced at different homogenization pressures (50 to 200 MPa) and pH values (4.6 to 8.0). According to the results of variance analysis and response surface, the pH had more influence on oil droplet size and protein load than homogenization pressure. The model equations, which were obtained by response surface analysis, show that pH and homogenization pressure had the major effect on oil droplet size and protein load. Higher homogenization pressure decreased the average droplet size and the protein load. Homogenization at high pressure, as opposed to low pressure, causes no overprocessing, but the effect was pH-dependent. The average diameter of the oil droplets increased slightly by decreasing the pH from 8.0 to 6.5 and then increased dramatically toward the isoelectric point of whey protein (i.e., at pH 4.6). Moreover associated droplets were found at acidic pH and their size was increased at high temperature.