• Journal of the Society of Cosmetic Scientists of Korea
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• 제25권4호
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• pp.145-154
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• 1999

A novel retinol derivative, polyethoxylated retinamide(Medimin A) was synthesized, as an anti-aging agent. Collagen synthesis, skin permeation, stability, and toxicity of Medimin A were evaluated and compared with those of retinol and retinyl palmitate. In vitro collagen synthesis was evaluated by quantitative assay of $[^3H]-proline$ incorporation into collagenase sensitive protein in fibroblast cultures. For in vitro skin permeation experiments, Franz diffusion cells(effective diffusion area: 1,766 $cm^2$) and the excised skin of female hairless mouse aged 8 weeks were used, The stabilities of retinoids were evaluated at two different temperature($25^{\circ}C\;and\;40^{\circ}C$) and under UV in solubilized state and in O/W emulsion. To estimate the safety, acute oral toxicity, acute dermal toxicity, primary skin irritation, acute eye irritation and human patch test were performed. The effect of Medimin A on collagen synthesis was similar to that of retinol. The skin permeability of Medimin A was higher than those of retinol and retinyl palmitate. The Medimin A was more stable than retinol and retinyl palmitate. Medimin A was nontoxic in various toxicological tests. These results suggest that Medimin A would be a good anti-aging agent for enhancing bioavailability and stability.

• The Korean Journal of Pesticide Science
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• 제16권3호
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• pp.261-266
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• 2012

It is common to use many experiment animals to evaluate the toxicity of chemicals including pesticides. For protecting animal, the concepts of 3R (Reduction, Replacement, Refinement) were introduced and in vitro alternatives methods actively have been developed all over the world. Many experimental animals for toxicological tests have been used, so that it is important to establish the alternative methods. In this study, the alternative method using reconstituted human skin model (Keraskin$^{TM}$) was conducted for classification of skin irritation on pesticides. Sixteen formulations selected on the basis of the degree of irritation were treated by Keraskin$^{TM}$ test. The percent of cell viability was measured into the culture medium collected after treatment of the pesticides for 24-72 hrs. The skin irritations of formulations were evaluated by the cell viability. In this study, The 4 formulations with mild irritation in rabbits were evaluated as nonirritant, the 6 formulations with moderate and severe irritation were evaluated as irritant in human skin model test. We suggest that the alternative test using Keraskin$^{TM}$ model could be used as toxicity evaluation for primary irritation index (P.I.I.) score of greater than or equal to 2.1 of pesticides. The further studies should be required to apply for hazardous assessment of pesticides on alternative skin irritation methods because of the interindividual variability of the sensitivity of skin irritation on pesticides.

• Toxicological Research
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• 제31권2호
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• pp.97-104
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• 2015

The skin exposure to solar irradiation and photoreactive xenobiotics may produce abnormal skin reaction, phototoxicity. Phototoxicity is an acute light-induced response, which occurs when photoreacive chemicals are activated by solar lights and transformed into products cytotoxic against the skin cells. Multifarious symptoms of phototoxicity are identified, skin irritation, erythema, pruritis, and edema that are similar to those of the exaggerated sunburn. Diverse organic chemicals, especially drugs, are known to induce phototoxicity, which is probably from the common possession of UV-absorbing benzene or heterocyclic rings in their molecular structures. Both UVB (290~320 nm) and UVA (320~400 nm) are responsible for the manifestation of phototoxicity. Absorption of photons and absorbed energy (hv) by photoactive chemicals results in molecular changes or generates reactive oxygen species and depending on the way how endogenous molecules are affected by phototoxicants, mechanisms of phototoxcity is categorized into two modes of action: Direct when unstable species from excited state directly react with the endogenous molecules, and indirect when endogeneous molecules react with secondary photoproducts. In order to identify phototoxic potential of a chemical, various test methods have been introduced. Focus is given to animal alternative test methods, i.e., in vitro, and in chemico assays as well as in vivo. 3T3 neutral red uptake assay, erythrocyte photohemolysis test, and phototoxicity test using human 3-dimensional (3D) epidermis model are examples of in vitro assays. In chemico methods evaluate the generation of reactive oxygen species or DNA strand break activity employing plasmid for chemicals, or drugs with phototoxic potential.

• Journal of Pharmaceutical Investigation
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• 제32권1호
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• pp.35-40
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• 2002

We prepared a novel dosage form, peel-off type soft hydrogel using poly(vinyl alcohol), and evaluated the effect of skin penetration enhancer on the indomethacin release from soft hydrogel by in vitro permeation and in vivo absorption test. In this study, we used four enhancers-urea, dimethyl urea, 1,1,3,3-tetramethyl urea, and pirotiodecane (1-[2(decylthio)ethyl]azacyclopentane-2-one, $HPE-101^{circledR}$). In addition, we evaluated the primary skin irritation test of soft hydrogel using rabbit. From these results, we could find the pirotiodecane was a prominent enhancer, and soft hydrogel seemed to be safe and have no irritancy.

• Journal of the Society of Cosmetic Scientists of Korea
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• 제31권1호
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• pp.43-49
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• 2005

Recently, according as people who have sensitive skin increase, we've been giving more importance to the safety of cosmetics. Especially, preservative is known to be one of the main stimuli which cause side-effects of cosmetics. However, there have been few reports describing cell cytotoxicity, skin penetration, oil-aqueous phase partition, anti-microbial activity of preservatives and their correlation with skin irritation. The study is aimed to develop low irritable preservative system with phenoxyethanol, one of the most commonly used preservatives in cosmetics, considering various factors mentioned above. According to our results of cell cytotoxicity against human normal fibroblasts by means of MTT assay, phenoxyethanol showed the lowest cytotoxicity when compared to other preservatives tested (cytotoxicity: pro-pylparaben > butylparaben > ethylparaben > methylparaben > triclosan > phenoxyethanol), but human patch test for assessing shin primary irritation revealed that phenoxyethanol has higher skin irritation than methylparaben and triclosan. We performed in vitro skin penetration test using horizontal Franz diffusion cells with skin membrane prepared from hairless mouse (5 ${\~}$ 8 weeks, male) to evaluate the rate of skin penetration of preservatives. From the results, we found that the higher irritable property of phenoxyethanol in human skin correlates with its predominant permeability (skin penetration: phenoxyethanol > methylparaben > ethylparaben > propylparaben > butylfaraben > triclosan). Therefore, we made an effort to reduce skin permeability of phenoxyethanol and found that not only the rate of skin penetration of phenoxyethanol but also its skin irritation is dramatically reduced in formulas containing oils with low polarity. In the experiments to investigate the effect of oil polarity on the oil-aqueous phase partition of phenoxyethanol, more than $70\%$ of phenoxyethanol was partitioned in aqueous phase in formulas containing oils with low polarity, while about $70 {\~} 90\%$ of phenoxyethanol was partitioned in oil phase in formulas containing oils with high polarity. Also, in aqueous phase phenoxyethanol showed greater anti-microbial activity. Conclusively, it appears that we can develop less toxic preservative system with reduced use dosage of phenox-yethanol and its skin penetration by changing oil composition in formulas.

• Journal of Life Science
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• 제15권2호
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• pp.267-272
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• 2005

The objective of this study is to suggest the potentialities of nanoliposome composed of ceramide as an anti-irritant against various irritants used in cosmetics. Ceramides are major structural components of the epidermal permeability barrier, which is known to play an essential part in human physiology by not only preventing the loss of water from the body but also protecting the body from external physical, chemical, and microbial insults. According to the results, better effects on reinforcement of skin barrier function and anti-irritation were obtained with nanoliposome composed of ceramide than with dispersed ceramide. And, we performed in vitro skin penetration test using horizontal Franz diffusion cells with skin membrane prepared from hairless mouse to evaluate the influence of nanoliposome composed of ceramide on the skin penetration of lactic acid in formulations. From the results, we found that the anti-irritation effects of nanoliposome containing ceramide were due to reduced penetration rate of irritants. Conclusively, we could develop a new anti-irritation system and apply this nanoliposome composed of ceramide to the final cosmetic products successfully.

• Journal of the Society of Cosmetic Scientists of Korea
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• 제50권3호
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• pp.279-288
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• 2024

This study investigates the efficacy of anti-acne cosmetics containing lactonic hydroxy acid, specifically gluconodeltalactone (GDL), in improving acne skin treatment. In sebaceous cells induced by linoleic acid, GDL at concentrations of 1.0 mg/mL or higher demonstrated a concentration-dependent inhibition of lipid synthesis. Antibacterial activity of GDL against Cutibacterium acnes (C. acnes) was confirmed through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Based on these in vitro results, a clinical test was conducted involving 65 participants to evaluate the effects of a anti-acne cosmetic formulation containing 3% GDL over an eight-week period. The results indicated a statistically significant improvement (p < 0.05) in both inflammatory acne lesions (papules, pustules, and nodules) and non-inflammatory lesions (comedones) from as early as two weeks of application, without any reported skin irritation. The results confirm that cosmetics with GDL can be used effectively and safely without long-term skin irritation, even for consumers with sensitive acne-prone skin.

• Analytical Science and Technology
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• 제11권2호
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• pp.79-87
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• 1998

Consumers have recently preferred to purchase extensive UV intercepting products, which are waterproof and free from side effects on skin. During the testing of cytotoxicity (in-vitro) in neutral red (NR) method, cell survival ratio of UV-B interceptors decreased to just above 0.08 w/v%, and it was observed that the UV-A interceptors the ratio also decreased to just above 0.06 w/v%. In addition patch-tests of inorganic UV interceptors resulted in no skin irritation even below 10.0 and 11.25. In absorption curves, UV-B was most suitable for octyl methoxycinnamate (OMC) and UV-A for butyl methoxy dibenzoylmethane (BMDM). For this reason, $Nylonpoly^{TM}$ UVA/UVB the material of OMC and BMDM coated with Nylon & polyethylene, was used as the organic UV interceptor. Zinc oxide (ZnO) and titanium dioxide ($TiO_2$) was used as inorganic UV interceptors. The appropriate mixture ratio of ZnO and $TiO_2$ was 6 to 4:6% of ZnO, 4% of $TiO_2$ and 5% of $Nylonpoly^{TM}$ UVA/UVB were all combined and added to our sunscreen cream. The SPF value of in-vitro was 38.9. In practical application, each sun protection factor (SPF) duration of oil-in-water (O/W) emulsion and water-in-silicone (W/S) emulsion containing sunscreen cream of the same content showed that W/S type of sunscreen cream was 5 times as durable as the other. Therefore, this product is fit for use in swimming, climbing or skiing. This research is to minimize skin trouble caused by UV interceptors and to make one with proper softness, skin safety and UV intercepting efficiency.

• Journal of the Korean Society of Food Science and Nutrition
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• 제33권4호
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• pp.641-645
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• 2004

Crude chondroitin sulfates extracted from midduck tunics (Styela clava) and munggae tunics (Halocynthia roretzi) were examined in vivo in order to be utilized as a cosmetic material which was followed by an in vitro assay. Examinations, such as acute oral toxicity, skin sensitization, acute eye irritation, and primary skin irritation, were peformed with a variety of laboratory animals. Phototoxic and photosensitization tests were not conducted since all chondroitin sulfates failed to absorb U.V. light at the range of 280 to 420 nm. In acute dermal and eye irritation, both specific clinical signs and dead cases were not demonstrated during the test period, but crude chondroitin sulfates from midduck and munggae tunics, and standard chondroitin sulfate from bovine trachea were showed 2.5, 1 and 1.25 of acute ocular irritation index (A.O.I.), respectively. In the case of skin sensitization, crude chondroitin sulfate from midduck tunics exhibited neither specific clinical signs nor dead cases in the entire course of the examination. While in acute oral toxicity, crude chondroitin sulfates from both midduck and munggae tunics found neither specific clinical signs nor dead cases during the test, and LD50 was suspected to be over 2 g/kg. Based on this study, it was proven that crude chondroitin sulfates from either midduck or munggae tunics can be used safely as a cosmetic material.

• Journal of the Korean Applied Science and Technology
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• 제19권2호
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• pp.79-85
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• 2002

The cutaneous tolerability of detergent formulations can be improved by means of suitable additives. They complex the surfactant molecules lowering the concentration of their free monomeric species. Proteins derivatives used as additives for detergency are usually prepared by partial hydrolysis of plant reserve proteins. The main purpose of the hydrolytic cleavage is to make them water soluble and suitable for liquid products. Water solubility and stability are obtained by means of complexation with surfactants which also increase their actual hydrophobicity, an important parameter affecting cosmetic properties of proteins. Transepidermal water loss (TEWL) and electric capacitance (EC) have been adopted as investigation technigues to evaluate the skin integrity/damage in vitro tests, The performance of native wheat protein / surfactant complexes has been compared with traditional protein hydrolysates as detergent additives. The results show a noticeable reduction of skin irritation in surfactant formulations with addition of native wheat protein.