• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.39-43
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• 2005

The present study was carried out to investigate the skin irritation potential of oregano oil in rabbits. A volume of 0.5 ml of test article was applied to intact and abraded skins, respectively, for 24 h in 6 healthy male New Zealand White rabbits. Parameters measured during 72 h observation period were mortality, clinical signs, body weight changes, and local irritation. Treatment-related toxic symptoms, as evidenced by anorexia and decreased locomotor activity, were observed in all rabbits tested. Two rabbits out of the 6 total died on day 2 after the application of test article due to treatment-related toxicity. The mean body weight of test animals decreased progressively during the 72 h observation period. All animals showed very slight edema at 24 h and then recovered at 72 h. These animals also showed very slight to severe erythema and/or slight eschar formation at both 24 h and 72 h. The eschar formation induced by oregano oil was not recovered at the end of additional 11-day recovery period. Based on these results, it was concluded that a single dermal application of the undiluted oregano oil caused an increased incidence of clinical signs and death and a decrease in the body weight and showed a primary irritation index score of 2.79 indicating moderate irritation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.17 no.1
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• pp.64-80
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• 1991

The SKINTEX Method is based on a two-compartment physico-chemical model which includes a Biomembrane Barrier in compartment one and an organized macromolecular matrix in compartment two. Test samples absorb onto or permeate through the keratin/collagen Biomembrane Barrier and then can interact with the organized macromolecular matrix. Changes in the integrity of the barrier release a dye indicator: Changes in the matrix can alter its transparency. The sum of these two responses is read spectrophotometrically at 470nm. An early investigation of 950 chemicals and formulations in the SKINTEX System produced results which were 89% concordance to in vivo Draize dermal irritation results obtained with 24-hour occluded application of test samples with-out abrasion and standard scoring. Alkaline materials were analyzed in a specialized SKINTEX AMA Protocol. In this early study, the model did not distinguish nonirritant test materials and formulation with PDII(Primary Dermal Irritation Index)in the range from 0 to 1.2, A High Sensitivity Assay Protocol(HSA)was developed to amplify the changes in both compartments of this model and provide more accurate calibration of these changes. A study of 60 low irritation test samples including cosmetics, household products, chemicals and petro-chemicals distinguished nonirritants with PDII $\leq$ 0.7 for 26 of 30 nonirritants. A second protocol was developed to evaluate the SKINTEX model predictability with respect to human irritation. The Human Response Assay (HRA )has been optimized based on differences in penetration and irritation responses in humans and rabbits. An additional 32 test materials with different mechanisms and degrees of dermal toxicity were evaluated by the HRA. These in vitro results were 86% concordant to human patch test results. In order to further evaluate this model, a Standard Chemical Labelling (SCL) Protocol was developed to optimize this system to predict Draize dermal irritation results after a 4-hour application of the test material. In a study of 52 chemicals including acids, bases, solvents, salts, surfactants and preservatives, the SCL results demonstrated 85% concordance to Draize results for a 4-hour application of test samples on non-abraded rabbit skin. The SKINTEX System, including three specialized protocols, provided results which demonstrated good correlation to the endpoint of dermal irritation in man and rabbits at different application times.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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• pp.164-173
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• 2012

Objectives: Epichlorohydrin is a material that has been predicted to have high volatility and strong toxicity and is used normally in working area. Therefore, the hazardous and dangerous level and the foreign management system about epichlorohydrin should be invested at home and abroad and through hazard assessment for occupational environment measurement and exposure status of industrial workers in domestic working area. Methods: To assess risk and to suggest Development and Adoption to prevent health damage of workers owing to the epichlorohydrin exposure, the hazardousness and dangerousness of epichlorohydrin and its practical examples and regulation level for domestic and abroad health impairment are researched on the base of various references. Results: The epichlorohydrin caused skin and mucus membrane irritation, respiratory paralysis, kidney and live damage under the influence of acute toxicity and in animal study, it was confirmed as a doubtful carcinogenic substance to trigger reducement of sperm number and reproduction ability, abnormal spermatogenesis, mutagen, increase of forestomach epithelium and occurrence of papilloma and so on, as well as it induced stimulus asthma and allergic contact dermatitis for exposure workers. Conclusions: Epichlorohydrin was found to occur allergic contact dermatitis, carcinogenesis doubt and reproduction toxicity and was verified as a material which would be established reinforcement of management level to care health of handlers, such as denotement dangerousness of skin absorption.

• Journal of Environmental Health Sciences
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• v.5 no.1
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• pp.1-9
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• 1978

Biological safety, physico-chemical and microbiological experiments were carried out in order to study the possibility of radiation sterilization on medical products, such as polyethylene and polystyrene bottles, gauze sponges and surgical silk suture. Results are as follows: 1. Biological test on plastic samples as to acute systemic toxicity, eye irritation, skin irritation, pyrogen, haemolysis showed satisfactory results. But physico-chemically, the oxidizable matter, nonvolatile residues, residue on ignition seemed to be increased slightly in irradiated samples, though the experimental results were within the range of U.S.P. 19, N.F. and K.P. III. 2. After irradiation, both plastic and gauze sponges showed considerable decrease in pH. 3. Most medical products were sterilized by 1.5 Mard. For the sterilization of the suigical silk suture, 4.5 Mrad is required dul to its radiation resistant micro-organisms. 4. Biologically, total dose of 2.5 Mrad was safe enough to sterilize the medical products, and physico-chemically the results are acceptable according to U.S.P. 19 and K.P. III. However, better results may be expected when the quality of material and additives are improved.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.2
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• pp.101-105
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• 2004

Purpose: Paraquat is the most commonly used herbicide in Korea. Exposure to paraquat through the skin has resulted in local irritation or inflammation of varying degree, sometimes severe. The purpose of this study was to review the patients with paraquat poisoning by skin absorption. Methods: We analysed retrospectively the clinical and laboratory findings of 45 patients with paraquat poisoning after dermal exposure, who were admitted to Soonchunhyang University Cheonan Hospital from January 1999 to December 2003. Results: Among 870 cases of paraquat poisoning, 45 cases were exposed to paraquat through the skin. The peak incidence was the fifth decade($40\%$). The clinical symptoms were pain, pruritus, nausea, and vomiting. The major skin lesions were generalized vesicobullae and necrotic erosion in face, scrotum, trunk, upper and lower extremities and etc. All patients were survived after skin contact or inhalation of paraquat. Conclusion: This study illustrates the extreme toxicity of paraquat and demonstrates that lethal quantities of paraquat may be absorbed if repeated exposure to it. Stricter precautions, including the mandatory use of protective clothing, should be recommended whenever this material is used.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.2
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• pp.174-181
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• 1996

The novel synthesis of 3-aminopropyl dihydrogen phosphate(3-APPA; 3-Aminopropane phosphoric acid), and its applicability to the skin as a cosmetic raw material in terms of its efficacy and toxicology were presented. The phosphorylation of 3-amino-1-propanol was carried out via cyclization into 6-membered 2, 6-oxaza-phosphoryl ring in the presence of phosphorous oxychloried and an organic base. The subsequent ring-opening hydrolysis and crystallization afforded the highly purified product in 90% isoloated yield. The method is much superior to the previous literature phosphorylation methodsm, as the procedure is simple and high-yielding. To confirm the efficacy of 3-APPA, several activities related to anti-aging capacity were measured. In-vitro human fibroblast, linear and 3-dimensional collagen matrix culture revealed that 3-APPA stimulated the proliferation of fibroblasts, and enhanced the synthesis of collagen, which showed 3-APPA's potency for skin wrinkle reduction. The toxicolgical aspect of 3-APPA was also extensively examined. In vivo toxicity tests such as acute oral toxicity, eye irritation, human patch, and the repeat insult human patch test proved 3-APPA to be a safe material. Thus 3-APPA can be used as an effective anti-aging agent for various cosmetic formulations.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1125-1131
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• 2009

Lophatheri Herba, Patriniae Radix, Alli tuberosi Herba, and Menthae Herba have long been used externally for treatment of injuries or inflammations in Korea. This study was carried out to examine the anti-dandruff effect of the mixture made with equal parts of 70%-ethanol extracts of Lophatheri Herba, Patriniae Radix, Allii tuberosi Herba, and Menthae Herba (LPAM) and of each one above, compared with 1%-zinc pyrithione (Standard) used commercially as anti-dandruff. The results showed the mixture was more effective than each crude drug. The 10%-LPAM produced no toxicity in skin reaction test and eye irritation test, and showed significant antimicrobial activity against Pityrosporum ovale, the major cause of dandruff, and also showed significant anti-dandruff and itch-improvement effects on head skin.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.70-81
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• 2000

DA-5018 is a synthetic capsaicin derivative under development as a non-narcotic a analgesic ag$\varepsilon$nt. DA-50 18 showed a potent analgesic activity against acute and chronic pain m model(Tablel, 2.), but it had a narrow margin of safety. DA-5018 did not bind to opioid(${\kappa}, {\delta}, {\mu}$), NKl, CGRP receptors in vitro and its analgesic effect was not antagonized by naloxone, a and it did not develop analgesic tolerance. In addition DA-5018 had no inhibitory effects against c cyclooxygenase and 5-lipooxygenase activities. DA-5018 significantly increased the relcase of substance P from the slices of the rat spinal cord. These results suggest that DA-50 18 is not a narcotic nor aspirin-like analgesic and the release of substance P is one of analgesic mechanism of action of DA-5018. We found that DA-5018 was almost ten times more potent and was at l least IOO-times less irritable compared to capsaicin. Accordingly development of topical formula was adopted. Topical formula was desiged and screened by flux test of DA-5018 using hairless mouse skin and several formulas were selected. With these topical formulas we a assessed the analgesic efficacy and carried out the toxicity, skin irritation and pharmacokinetic studies. In streptozotocin-induced hyperalgesic rat and 50 % galactose-fed hyperalgesic rat as diabetic pain models, DA-5018 cream increased the pain thresh이ds up to 77.0% and 24.4% respectively, while Zostrix-HP(capsaicin cream) incr$\varepsilon$as cd by 65.9% and 21.0%. DA-5018 c cream showed a good analgesic effect as welI in FCA-induced arthritic rat. DA-5018 cream did not show any toxicological signs in acute and chronic toxicity test and had little skin irritation in car swclIing and scratching t$\varepsilon$st. Pharmacokinetics of DA-50 18 were studied after topical application of ${14}^C$-Iabelled or unlabelIed DA-5018 cream. Plasma and skin concentrations c except applied skin wcre below the dctection limit and after 7-day cummulative application, plasma concentrations were also below detection limit DA-50 18 may have an advantag$\varepsilon$ ov$\varepsilon$r c capsaicin and is now being developed as a topical agent for the treatment of pains. DA-50 18 cream was approved for Korean IND and is now under a Phase II clinical study for arthritic pain a after finising Phase I study. DA-50 18 was also liscensed out to Stiefel Company in America in

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.1
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• pp.31-38
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• 2013

To substitute animal test, skin equivalents (SEs) have been developed for skin irritation and corrosion test. Recently, we have developed new SEs containing Cervi cornus Colla (CCC). In the present study, we used the SEs for cutaneous cytotoxicity test. Sodium dodecylsulfate (SDS) or sodium carbonate was applied to the SEs-, and the epidermal damage by H&E and immunohistochemical stains was evaluated. Our results showed that SDS or sodium carbonate affected the epidermal part of SEs containing CCC in a dose-dependent manner and decreased the expression of p63. It is concluded that SEs containing CCC could be used for an alternative model of animal test and would be greatly helpful in the development of in vitro irritation and corrosion test.

• Safety and Health at Work
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• v.10 no.4
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• pp.409-419
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• 2019

Although the rare earth elements (REEs) recycling industry is expected to increase worldwide in hightech industry, regulations for worker safety have yet to be established. This study was conducted to understand the potential hazard/risk of REE recycling and to support the establishment of regulations or standards. We review the extensive literature on the toxicology, occupational safety, and health issues, and epidemiological surveys related to the REEs, and propose suitable management measures. REE recycling has four key steps such as collection, dismantling, separation, and processing. In these processes, hazardous substances, such as REEs-containing dust, metals, and chemicals, were used or occurred, including the risk of ignition and explosion, and the workers can be easily exposed to them. In addition, skin irritation and toxicities for respiratory, nervous, and cardiovascular systems with the liver toxicity were reported; however, more supplementary data are needed, owing to incompleteness. Therefore, monitoring systems concerning health, environmental impacts, and safety need to be established, based on additional research studies. It is also necessary to develop innovative and environment-friendly recycling technologies, analytical methods, and biomarkers with government support. Through these efforts, the occupational safety and health status will be improved, along with the establishment of advanced REE recycling industry.