• 한국응용과학기술학회지
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• 제35권4호
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• pp.1478-1486
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• 2018

Liquid crystals offer plenty of useful activities as improving the stability of emulsion, increasing moisturizing power, drug release, improving skin feeling and visual effect for cosmetics fields. In order to prepare stable semi-transparent gel emulsion, liquid crystal emulsification method was used. The emulsion stabilities of systems containing glycerin, fatty alcohols, surfactants, water and oil were investigated at various temperatures as time passed. The stabilities of all emulsions were evaluated by means of a polarizing microscope, SEM, rheometer, colorimeter and DSC. Even though the samples stored at $50^{\circ}C$ thermostatic chamber were occurred the reduction of hardness, turbidity and ${\Delta}H$ and the peak shift, the semi-transparent gel emulsion was very stable without separation between water and oils phase in emulsion.

• 한국산학기술학회논문지
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• 제22권1호
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• pp.81-86
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• 2021

화장품 산업은 정밀화학분야로 기술집약적인 산업이며 세계적으로 지속적인 성장률을 보이고 있다. 이러한 화장품 산업에서 시장 점유율을 높이기 위해 과거에는 기능적 측면이 주로 강조가 되어 왔으나, 최근에는 국내외적으로 화장품의 우수한 성능과 더불어 시각적 효과로 소비자의 관심을 유도하려는 노력이 고조되고 있다. 이에 따라 화장품 제조업체에서는 화장품 에멀젼을 캡슐화하고 에멀젼 캡슐의 형태, 색상 및 질감 등을 다양하게 변형시킬 수 있는 기술을 다방면으로 시도하고 있는 상황이다. 에멀젼을 캡슐화하는 기본 방식은 에멀젼 저장소에 에멀젼을 채워 넣고 노즐을 통해 에멀젼을 낙하시키는 방법으로 업체에서 가장 쉽게 이용할 수 있다. 그러나, 에멀젼을 캡슐레이션하는 기존 방식은 캡슐의 사이즈를 줄이는 데 한계가 있다. 본 연구에서는 이러한 기존 방식의 한계를 이론 및 수치해석방법으로 고찰하였으며, 이러한 방식의 문제를 해결하기 위한 대안책으로 미세유체역학(Microfluidics)을 적용하기 위하여 마이크로 채널 내에서 발생하는 에멀젼 캡슐레이션 현상을 연구하였다.

• 대한화장품학회지
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• 제40권3호
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• pp.227-236
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• 2014

본 연구에서는 친수성 계면활성제와 친유성 계면활성제가 조합된 다양한 HLB (Hydrophilic Lipophilic Balance) 값을 갖는 유화 시스템의 조건에서, required HLB 값이 각기 다른 오일들을 적용하여 제조한 O/W 및 W/S 에멀젼들의 특성 및 유화 안정성을 조사해 보았다. 그 결과 O/W 에멀젼은 유화제의 HLB 값이 낮을수록 점도가 높고, 유화입자는 작고 조밀한 경향을 나타내었으며, 원심분리에서도 더 안정한 경향을 나타내었다. W/S 에멀젼은 유화제의 HLB 값이 높을수록 유화입자는 작고 조밀해지는 경향을 나타내었으며, 원심분리에서도 더 안정한 경향을 나타내었다. 그러나 W/S 에멀젼은 시간이 경과할수록 모든 유화제의 HLB 조건에서 점도가 낮아지는 경향이 나타나 장기 안정도에서는 불안정한 특성을 나타내었다. 이번 연구의 결과는 O/W 에멀젼은 HLB 값이 높은 비이온 계면활성제의 적용이 적합하며 W/S 에멀젼은 HLB 값이 낮은 비이온 계면활성제의 적용이 적합하다는 기본 이론과 상반되는 결과로서 앞으로의 화장품 연구 개발 시 유용한 연구 자료가 될 것으로 사료된다.

• 대한화장품학회지
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• 제24권3호
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• pp.111-115
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• 1998

We investigated the stability of all-trans-retinol on the liquid crystalline O/W emulsion composed of mainly alkyl polyglycerine, alkyl polyglucose and glycerine, and compared the activity of all-trans-retinol in the various forms of liquid crystal. Under certain conditions, novel liquid crystalline gel was formed around oil droplets, and layers of this liquid crystalline gel were very wide and rigid. (SWLC; Super Wide Liquid Crystal) SWLC was very helpful to stabilize retinol in O/W emulsion. After storage at 45 C for 4 weeks, all-trans-retinol in O/W emulsion composed of SWLC retained above 85% of the activity upon HPLC analysis, whereas those within no liquid crystalline emulsion gave 47% and normal liquid crystalline emulsion composed of fatty alcohols gave 40 60%. Retinol in oil phase is nealy insoluble in pure water, but in cosmetic emulsion systems can be slightly solubilized into water because emulsifiers and polyols in emulsion systems function as solubilizers. In this case, water in outer phase acts as a media for oxygen transporation$.$and thus destabilizes retinol. As a result, retinol in O/W emulsion has a tendency to become unstable. SWLC surrounding oil droplet which contains retinol is wide and rigid, therefore reduces contact between inner phase and outer phase To make SWLC, properties of emulsifiers are very important phase transition temperature should be high, and the structure of surfactants should be bulky, and their ratio should be suitable to make rigid and wide liquid crystalline gel layer in order to reduce contact between retinol in inner phase and water in outer phase.

• KSBB Journal
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• 제27권4호
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• pp.207-214
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• 2012

Emulsions are mixture of immiscible liquids in which one is dispersed in all over the other. They have been applied to many applications including cosmetics, foods, drug delivery system (DDS), fine chemicals, and chemical separations. Especially, emulsion technology is one of the most useful technique to formulate cosmetics such as eye cream, foundation, and foam cleansing. In general, the emulsions can be generated by mechanical agitation of two immiscible fluids. However, the emulsions obtained by conventional method have limited in stability, monodispersity, and complicate process. We describe here preparation techniques of representative cosmetic emulsions such as liposome, liquid crystal emulsion, nanoemulsion, multiple emulsion, and pickering emulsion. Furthermore, various factors which can control the physical properties of each cosmetic emulsions are briefly discussed.

• 대한화장품학회지
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• 제24권3호
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• pp.123-128
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• 1998

Dihydroxyacetone (DHA) has been used as a self tanning agent and many emulsion formulations containing DHA have been studied. In an emulsion, many factors which have negative effect on DHP and the resultant DHA decomposition can destabilize the emulsion base. In this study, two kinds of emulsion with 5％ DHA were prepared, O/W type emulsion and Multilamellavesicle (MLV) type emulsion to compare the stabilization effects of both emulsions on the DHA. The OHA concentration was analyzed quantitatively by high performance liquid Chromatography (HPLC), also the pH and viscosity of both emulsions were measured for stability. This process was carried out over 4 months. For HPLC, a bondaclone $C_{18}$ column with a mobile phase of distilled water and UV detector were used. The results of these experiment showed that DHA is more stable in an MLV emulsion than it is in an O/W type emulsion.

• Journal of Pharmaceutical Investigation
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• 제37권4호
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• pp.217-222
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• 2007

To develop cleansing tissue composed of silicone multiple emulsions which could easily remove make-up residues and confer skin protecting effect without damaging skin, we formulated various silicone multiple emulsions and evaluated the physicochemical properties including viscosity, cleansing effect, and safety effect. Also, cleansing tissue incorporated with silicone multiple (W/Si/W) emulsion was stored for 6 months, and judged its stability through microscopes under accelerated and long-term condition. Cleansing effect was evaluated by chromameter. Skin hydration effect was determined by corneometer and incorporation effect into non-woven fabric cotton was evaluated by volunteer survey. Low viscosity ranged from 400 centipoise (cP) to 1,000 cP was obtained from a stabilized W/Si/W emulsion containing more than 10% volatile silicone. Mean diameter of fresh W/Si/W emulsion was $20{\mu}m$, but after storage for 3 months at $45^{\circ}C$, the particle size of the W/Si/W emulsion increased up to $50{\mu}m$. Both W/Si/W emulsion-incorporated cleansing tissue and commercial product showed equally good cleansing effect. In addition, skin allergies such as erythema, edema, scaling itching, stinging, burning, tightness and prickling were not observed through macroscopic examination. From the transepidermal water loss results, the cleansing tissue consisting of W/Si/W emulsion showed superior hydration effect to commercial product. In conclusion, this study suggests cleansing tissue using W/Si/W emulsion could be used for an excellent efficacy compared with commercialized cleansing tissue.

• 한국미생물·생명공학회지
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• 제41권3호
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• pp.320-326
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• 2013

이전 연구에서 저자들은 담쟁이덩굴 줄기 추출물의 항산화 및 세포 보호 효과를 연구하였다. 본 연구에서는 우수한 활성을 갖는 담쟁이덩굴 줄기 추출물의 피부흡수를 증진시키고자 이를 함유한 나노에멀젼을 제조하고 물리적 특성 및 피부흡수능을 평가하였다. 고압유화기(microfluidizer)를 이용하여 제조한 나노에멀젼은 평균 입자 크기가 302 nm를 나타내었으며 포집 효율은 86% 이상으로 나타났다. 나노에멀젼은 단분산의 입도 분포를 나타내었고 고압유화과정을 거치지 않은 일반 에멀젼보다 2주간 높은 안정성을 나타내었다. Franz diffusion cell을 이용하여 제조된 담쟁이덩굴 추출물 함유 나노에멀젼의 피부흡수능을 평가하였다. 그 결과 대조군으로 사용된 1,3-butylene glycol 용액이 32.59%의 피부흡수율을 나타내었고, 나노에멀젼은 42.47%의 피부 흡수능을 나타내었다. 또한 담쟁이덩굴 줄기 추출물의 화장품에 있어 천연 항균제로써의 응용 가능성을 연구하고자 에틸아세테이트 분획의 피부 상재균에 대한 항균작용을 측정하였다. 항균활성 측정결과 담쟁이덩굴 줄기 추출물은 Staphylococcus aureus, Bacillus subtilis에 대해 항균활성을 나타내었으며, 화장품에 주로 사용되는 항균제인 methyl paraben 보다 높은 항균활성을 가지고 있음을 확인하였다. 이상의 결과들은 담쟁이덩굴 줄기 추출물을 함유한 나노에멀젼이 피부흡수능 증진을 통해 향후 화장품 제형으로서 이용가능성이 큼을 시사한다. 또한 담쟁이덩굴 줄기 에틸아세테이트 분획의 Gram (+) 세균에 대한 항균활성을 바탕으로 이전 연구에서 밝혀진 항산화 활성 및 세포보호효과와 더불어 기능성원료로서 응용 가능성이 큼을 시사한다.

• 대한화장품학회지
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• 제24권3호
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• pp.38-44
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• 1998

The skin permeation and the skin primary irritation of two UV filters from caprylic capryl triglyceride (oil), oil in water (O/W) and water in oil (W/O) emulsions, were evaluated. We selected octyl moth-oxycinnamate (OMC) broadly used in cosmetics and polymeric sunscreen agent (PSA, average MW: 2,000) synthesized by the coupling reaction of 2-ethylhexyl 4-hydroxycinnamate with poly vinylbenzyl chloride, as model UV filters. For in vitro skin permeation experiments, Franz diffusion cells (effective diffusion area:1.766cm) and the excised skin of female hairless mouse aged 8 weeks were used. Oil or emulsion containing UV filters was applied in the donor compartment. The skin primary irritation was evaluated with fe-male guinea pigs (8-10 weeks,350-400 g). In oil and emulsions, the skin permeability and the skin primary irritation of PSA were lower than those of OMC. The skin permeability of UV filters was lower when they were in oil-in-water emulsion (OIW) than water-in-oil emulsion (W/O). We suggest that O/W system would be more useful when compared with W/O system, and PSA could be a good candidate for a future sunscreen agent for reducing the skin irritation.

• 대한화장품학회지
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• 제3권1호
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• pp.12-18
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• 1973