• Journal of the Korean Applied Science and Technology
• /
• v.35 no.4
• /
• pp.1478-1486
• /
• 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.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.81-86
• /
• 2021

The cosmetic industry is technology-intensive in the field of fine chemistry and continues to grow globally. The functional aspects have been mainly emphasized in the past to increase the market share in these cosmetics industries. Recently, however, efforts have been made to attract the attention of consumers to the visual effects as well as the excellent performance of cosmetics at home and abroad. Accordingly, cosmetic manufacturers are trying various technologies that encapsulate the cosmetic emulsion and modify the shape, color, and texture of the emulsion capsule. The basic and easiest method of encapsulating emulsion is dropping the emulsion through the nozzle from emulsion storage. On the other hand, the existing method of encapsulating emulsion has a limit in reducing the size of the capsule. In this study, the limit was shown by theory and numerical analysis method, and the emulsion encapsulation phenomena occurring in the micro-channel were studied to apply microfluidics as an alternative.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.40 no.3
• /
• pp.227-236
• /
• 2014

In this study, O/W and W/S emulsions were prepared by combining oils having different required hydrophilic lipophilic balance (HLB) values under the diverse conditions of HLB values composed of a hydrophilic surfactant and a lipophilic surfactant and their stability was investigated. Results showed that the higher the viscosity of O/W emulsions was as the lower the HLB value of emulsifier and emulsion particle showed a tendency to be a smaller and compact and stabler in centrifugal filtration. W/S emulsions also showed a similar tendency to be a smaller and compact as HLB values of emulsifier was higher and stabler in centrifugal filtration. However, the viscosity of W/S emulsion tended to get lower in HLB conditions of all emulsifiers as the time passed. This indicated that the emulsions had an unstable feature in long-term stability. In conclusion, the results showed opposite to the known theory that O/W emulsion is proper to be applied by nonionic surfactant with a high HLB value and W/S emulsion to be applied by nonionic surfactant with a low HLB value and provide useful information for the cosmetics research and related areas.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.24 no.3
• /
• pp.111-115
• /
• 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
• /
• v.27 no.4
• /
• pp.207-214
• /
• 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.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.24 no.3
• /
• pp.123-128
• /
• 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
• /
• v.37 no.4
• /
• pp.217-222
• /
• 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.

• Microbiology and Biotechnology Letters
• /
• v.41 no.3
• /
• pp.320-326
• /
• 2013

In a previous study, we investigated the antioxidative and cellular protective effects of Parthenocissus tricuspidata stem extracts. In this study, we prepared nano-emulsion containing P. tricuspidata stem extract to improve skin permeation. The particle size of the nano-emulsion using the microfluidizer was 302 nm. Its loading efficiency was over 86%. The size distribution of the nano-emulsion took a monodispersed form and the nano-emulsion was more stable than typical emulsion without using microfluidizer during a 2 week period. In vitro skin permeation study of nano-emulsion containing P. tricuspidata stem extracts was carried out using Franz diffusion cell. The 1,3-butylene glycol used as a control group had 32.59% skin permeation efficiency. The skin permeation efficiency of the nano-emulsion was 42.47%. Also, we observed the antibacterial activity of the ethyl acetate fraction on skin flora for prospective applications as a natural antimicrobial. The ethyl acetate fraction had antibacterial activities higher than methyl paraben on Staphylococcus aureus, and Bacillus subtilis. These results indicate that nano-emulsion containing P. tricuspidata stem extracts could possess valued applications in cosmetic formulations for improving skin permeation. Also, based on the antibacterial activities on skin flora, antioxidative and cellular protective effects shown in our previous study, we suggest that P. tricuspidata stem extracts could be used as functional cosmetic materials.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.24 no.3
• /
• pp.38-44
• /
• 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.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.3 no.1
• /
• pp.12-18
• /
• 1973