• Journal of the Korean Applied Science and Technology
• /
• v.26 no.2
• /
• pp.117-123
• /
• 2009

Caprylic/Capric triglyceride-in-water emulsions stabilized by Nikkol HCO-60 and HCO-10 were prepared using emulsion inversion point method at different HLB values. Emulsions with various droplet sizes were formed, and emulsion inversion point was detected by electrical conductivity. The change in emulsion droplet sizes and long term stability were monitored using laser scattering method and visual method. The droplet sizes and stability of emulsions were affected by HLB of surfactant. At emulsion inversion point, the water volume fraction increased as the HLB of surfactants decreased. According to our analysis, this resulted from a tendency of forming the W/O (water-in-oil) emulsion as the HLB of surfactants was decreased. The emulsion inversion point was clearly detected by the microscope and the electric conductivity meter. Nanometer-sized emulsion was obtained at the optimum HLB by using emulsion inversion point method. The main pattern of instability of emulsions in HLB 12 and 13 systems was Ostwald ripening. However, The patterns of instability of emulsions below 11 of HLB systems were Ostwald ripening and coalescence. All emulsions produced with surfactants in the range of HLB 8-13, creaming caused by density difference between water phase and oil phase.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2004.11a
• /
• pp.216-219
• /
• 2004

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.10a
• /
• pp.294-294
• /
• 1998

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.38 no.3
• /
• pp.201-207
• /
• 2012

The influence of different dilution procedures on the properties of oil-in-water (O/W) nano-emulsions obtained by dilution of oil-in-ethanol (O/E) microemulsions with water has been studied. The system water/ethanol/nonionic surfactant/silicone oil with ethanol was chosen as model system. The dilution procedures consisted of adding water (or microemulsion) stepwise. By mixing O/E microemulsions into water, nano-emulsions with droplet diameters of 30 nm were obtained. In contrast, by mixing water into O/E microemulsion, emulsions with diameter of 400 nm were obtained The dilution methods were shown to be a key factor determining the properties of the emulsions. There were no change in diameters of nanoemulsion droplets against time, however sizes of droplets in the emulsion with larger droplets were increased with time and the mechanism of unstability was thought to be Ostwald ripening.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.23 no.3
• /
• pp.108-114
• /
• 1997

The skin permeation study has two meanings in cosmetics. One is how to promote the skin permeation of active meterials for improving their bioavailabilities and the other is how to decrease it of irritants for reducing their skin side effects. In this study, we selected methyl paraben, one of the preservatives, as a model irritant and tried to reduce the skin irritation by the decrease of skin permeation. Furthermore, the relationship between skin permeation and skin primary irritation was discussed. For in vitro skin permeation experiments, Franz type diffusion cells and the excised skin of female hairless mouse from 8 weeks old were used. The donor compartment was charged with oil only or O/W emulsion containing 0.3% MP. We selected 19 oils, including esters, triglycerides, plant oils, hydrocarbons, and alchols, which are broadly used in cosmetics. We evaluated with female guinea pig. The skin permeahility of MP from the oils showed following order: ester oils > triglycerides > plant oils > hydrocarbons > alcohols. We considered that this result was based on the different effect of each oil on the barrier function of stratum corneum. In O/W emulsion containing each oil, the skin permeability of MP decreased as the oil/water partition coefficient of MP increased. The skin primary irritation increased as the skin permeability of MP increased. In conclusion, we suggest that the skin irritation could be reduced by the decrease of skin permeability of MP, which may be obtained by the good selection of oils in cosmetic preparations.

• Journal of Pharmaceutical Investigation
• /
• v.29 no.4
• /
• pp.323-327
• /
• 1999

To protect ${\beta}-carotene$ at the stomach and to release rapidly at the intestine we prepared alginate beads containing ${\beta}-carotene$. ${\beta}-carotene$ and alginate solution was homogenized and prepared o/w emulsion was prepared. It was poured into $Ca^{2+}$ solution through syringe needle. The gel was formed spontaneously and alginate beads containing ${\beta}-carotene$ were prepared. ${\beta}-Carotene$ was incorporated into the beads more than 95%. The release rate of ${\beta}-carotene$ was dependent on the concentration of $Ca^{2+}$, ${\beta}-carotene$ and surfactants. However, the concentration of alginate did not affect the release rate of ${\beta}-carotene$. The high concentration of $Ca^{2+}$ slowed down the release rate of ${\beta}-carotene$. The addition of surfactants in the ${\beta}-carotene$beads increased the release rate of ${\beta}-carotene$ in the order of Tween 80 > Cremophor > Span 20. The contents of ${\beta}-carotene$ and diameter of ${\beta}-carotene$ beads did not change significantly at $50^{\circ}C$ for 20 days.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.4 s.48
• /
• pp.471-477
• /
• 2004

Exposure to elevated temperatures, chemical (active oxigen), or physical stress (UV light) induces immediate physiological response, the expression of heat shock proteins in cells. Thus, cells with elevated Heat Shock Protein levels become more tolerant to stress conditions that are otherwise lethal. First, we studied on the new function of glucuronic acid (GA) as preventive material of skin aging. The application of the GA shows significant induction of Heat Shock Protein 70 kDa (HSP 70 kDa) in contrast to cells without it. GA at the concentration which can induce HSP 70 kDa, protects the cell death induced by second stress (heat shock and hydrogen peroxide) in NIH3T3 cells. Second, we studied on in vitro transdermal permeation characteristic of GA through the excised mouse skin. In this study, we compared the skin permeability of GA in water with O/W emulsion. As a result, skin permeation parameters of GA shows lag time 1.2 h, partition coefficient 0.114, permeation flult rate $0.83114 mg/cm^2/h.$ In case of lag time, O/W emulsion containing GA increase 2.48 h. Also, the total accumulation permeation content decreased in contrast to GA solution after 24 h. But it has long-term permeability of glucuronic acid. These results suggest that glucuronic acid could be a good cosmetic active ingredient.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.25 no.1
• /
• pp.23-36
• /
• 1999

Medimin A is a derivative of vitamin A which has been developed by coupling retinoic acid with polyethylene glycol(PEG) to enhance skin permeability and stability. We carried out the collagen synthesis and clinical test to examine the reducing effect of wrinkles by Medimin A. In vitro collagen synthesis was evaluated by quantitative assay of ($^3$H)-proline incorporation into collagenase sensitive protein in fibroblast cultures. Clinical test was evaluated by image analysis of skin replica, visual observation and self-estimated response of volunteers for 10 weeks. Medimin A stimulated about 40% in collagen synthesis. The area of main deep wrinkle on the skin replica was reduced 38.4% with topical application of O/W emulsion containing 0.2% Medimin A. The wrinkles on the eye region was also reduced 25.4%-44.1% by the visual observation and 93% of all volunteers responded that topical application of the O/W emulsion was showed some reducing effect of wrinkles after 10 weeks. From these results, we suggest that Medimin A is a potent anti-wrinkle agent by objective evaluation methods(in vitro collagen synthesis and image analysis of skin replica) and subjective evaluation methods(visual observation and self-estimated response of volunteers).

• Textile Coloration and Finishing
• /
• v.10 no.2
• /
• pp.29-36
• /
• 1998

Poly(L-lactide) microcapsules containing hydrophilic penetrate were prepared by interfacial precipitation method through solvent evaporation from w/o/w emulsion. Effect of four determinative process parameters on the particle size distributions, morphologies, and release properties of microcapsules coated with poly(L-lactide) was investigated. Moreover, susceptible functional cotton fabrics treated with the mentioned microcapsules were prepared and laundry test up to 15 times were done to determine fastness properties. As a result, the prepared poly(L-lactide) microcapsules with a more sharp-distributive, rounder, and more permeable membranes could be prepared by means of protective colloid concentration, solution volume and stirring rate.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.6
• /
• pp.1021-1026
• /
• 2000

The removal of cadmium, copper and chromium ions was carried in a phase transfer reactor using W/O(water in oil) microemulsion containing sodium di[2-ethylhexyl] sulfosuccinate(AOT) and isooctane system. Removal efficiencies and mass transfer rate of $Cd^{2+}$, $Cu^{2+}$ and $Cr^{3+}$ were increasing with increasing pH of aqueous solution. However, $Cr^{6+}$ was not extracted by W/O microemulsion with AOT/isooctane system. It was found that removal of heavy metal ions were required an attractive electrostatic interaction between the metal ions and W/O microemulsion. The relationship between mass transfer rate. Jo of $Cd^{2+}$, $Cu^{2+}$ and $Cr^{3+}$ and pH of aqueous solution by W/O microemulsion suggested.