• Biomolecules & Therapeutics
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• 제6권1호
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• pp.95-110
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• 1998

A 13-week dermal toxicity test was conducted to assess the toxicity of DA-5018, a capsaicin derivative. Three groups of Sprague-Dawley rats (10-15 males and 10-15 females) were treated with DA-5018 cream daily by dermal application at concentrations of 0.1%, 0.3% or 0.9% as 500 mg/kg for 13 weeks. One further group of rats (15 males and 15 females) received cream base at 500 mg/kg/day and acted as controls. One male receiving 0.3% DA-5018 cream died during the treatment period. But the animal did not show any signs of treatment-related toxicity until death. There were no local skin reaction of application site and systemic reaction to the treatment of DA-5018 creams in all experimental groups throughout treatment and recovery period. Weight gain and food consumption in animals that received DA-5018 creams appeared to be comparable to that of the controls. Laboratory analyses (hematology, urinalysis and opthalmoscopic examination) did not revealed pathological values. In biochemical investigations, an increase of glucose level associated with increased food consumption and some other significant changes were noted in the animals of both sexes received DA-5018 creams. But these changes were not considered to be of toxicological importance. Postmortem examination did not show macroscopic or histological alterations attributable to the DA-5018 treatments. Based on these results, NOAEL(no-observable-adverse-effect level) of DA-5018 cream if estimated to be over 500 mg/tg/day as 0.9% cream.

• Toxicological Research
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• 제16권4호
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• pp.302-309
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• 2000

The purpose of this study is to investigate toxic effects of iso-butylalcohol (iBA) in Sprague-Dawley (SD) rats under the exposure of 6 hours a day, 5 days a week for 13 weeks by inhalation, and to evaluate the occupational safety of iBA in comparison with the permissible exposure level (PEL) stipulated by the Occupational Safety and Health Administration (OSHA). iBA did not induce any abnormal changes from the aspects of clinical signs, feed consumption, ophthalmic test, urinalysis, hematology and blood chemistry during and at the terminal of the inhalation toxicity tests. We did not find any abnormal findings in the gross and microscopic observations due to the inhalation of iBA. There was no alteration in relative organ weights by the inhalation of iBA. No observed adverse effect level (NOAEL) of iBA was considered to be more than 3,000 ppm in rats under the inhalation of 6 hours a day, 5 days a week for 13 weeks. Fifty ppm of iBA, the PEL regulated by OSHA, is too conservative for working places. As iBA showed no abnormal observations in all the experimental parameters at any concentration under this experimental condition, we suggest that 150 ppm is safe enough for the PEL of iBA in the working areas, even taking into onsideration that OSHA lowered the PEL to 50 ppm for fear of the probable risk of its skin irritation.

• Toxicological Research
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• 제34권2호
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• pp.111-125
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• 2018

Solvents can be used in the manufacture of medicinal products provided their residual levels in the final product comply with the acceptable limits based on safety data. At worldwide level, these limits are set by the "Guideline Q3C (R6) on impurities: guideline for residual solvents" issued by the ICH. Diisopropyl ether (DIPE) is a widely used solvent but the possibility of using it in the pharmaceutical manufacture is uncertain because the ICH Q3C guideline includes it in the group of solvents for which "no adequate toxicological data on which to base a Permitted Daily Exposure (PDE) was found". We performed a risk assessment of DIPE based on available toxicological data, after carefully assessing their reliability using the Klimisch score approach. We found sufficiently reliable studies investigating subchronic, developmental, neurological toxicity and carcinogenicity in rats and genotoxicity in vitro. Recent studies also investigated a wide array of toxic effects of gasoline/DIPE mixtures as compared to gasoline alone, thus allowing identifying the effects of DIPE itself. These data allowed a comprehensive toxicological evaluation of DIPE. The main target organs of DIPE toxicity were liver and kidney. DIPE was not teratogen and had no genotoxic effects, either in vitro or in vivo. However, it appeared to increase the number of malignant tumors in rats. Therefore, DIPE could be considered as a non-genotoxic animal carcinogen and a PDE of 0.98 mg/day was calculated based on the lowest No Observed Effect Level (NOEL) value of $356mg/m^3$ (corresponding to 49 mg/kg/day) for maternal toxicity in developmental rat toxicity study. In a worst-case scenario, using an exceedingly high daily dose of 10 g/day, allowed DIPE concentration in pharmaceutical substances would be 98 ppm, which is in the range of concentration limits for ICH Q3C guideline class 2 solvents. This result might be considered for regulatory decisions.

• 한국환경농학회지
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• 제4권2호
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• pp.118-125
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• 1985

농약의 만성어독성을 평가하기 위한 노력의 일환으로 제초제인 butachlor에 대하여 송사리 (Oryzias latipes)을 대상으로 하여 90일간 아급성 어독성 실험을 실시하였고 또한 만성독성 평가를 위한 생물학적 검정어류로써 송사리의 타당성을 제고한 바 그 결과는 다음과 같다. 1) 송사리는 우리나라에서 고르게 분포하고 있는 소형 민물고기로써 시험기간중 대조군 등에서 산란 및 부화가 이루어져 풍부한 생물학적 자료와 함께 농약에 대한 만성 어독성 평가에 적합하다고 사료된다. 2) Butachlor의 0.16 ppm 처리군은 약간의 길이 성장감소와 산란된 수정란의 부화율이 감소되는 경향을 나타내었고, 0.04ppm과 0.01 ppm의 butachlor 처리군에서는 대조군과 비교할 때 별 다른 영향을 받지 않았음을 관찰할 수 있었다. 고로, butachlor는 송사리에서 0.04${\sim}$0. 16ppm의 MATC 값을 갖는 것으로 사료되며 또한 실험기간중 DO와 pH및 온도를 매일 측정한 결과 송사리에 영향을 주지 않았음이 입증되었다.

• Environmental Analysis Health and Toxicology
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• 제21권2호
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• pp.173-184
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• 2006

From the harmfulness expectation test conducted through a toxicity anticipation program, methylcyclohexane turned out to be harmful and simulative, but no carcinogenicity was anticipated. In a four-hour acute inhalation toxicity test, the result showed that lethal concentration ($LC_{50}$) was 3,750 ppm (15,054 mg/L), which was identified as a harmful substance on the basis of the harmful substance classification standard $2 of the Industrial safety and health law. methylcyclohexane fell under the category $4(2,500 substance from the GHS standard acute toxicity harmfulness classification. Also, from subchronic inhalation toxicity test that included 6 hours a day, five days a week, and for 13 weeks, we could observe weight, activity, long term weight, blood and blood biochemical influence from the exposure of test substance. No-observed effect level (NOEL) was determined below $100{\sim}400ppm$ inboth male and female. This material falls under the Category 2 ($50{\sim}250ppm/6hours/90days$) in the GHS (Globally Harmonized System) standard trace long-term whole body toxicity repeated exposure, and can be classified as a harmful substance in accordance with the Industrial Safety and Health Law harmful substance standard $NOEL{\leq}0.5mg/L/6hr/90day$ (rat).

• Safety and Health at Work
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• 제2권1호
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• pp.34-38
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• 2011

Objectives: The antimicrobial activity of silver nanoparticles has resulted in their widespread use in many consumer products. Yet, despite their many advantages, it is also important to determine whether silver nanoparticles may represent a hazard to the environment and human health. Methods: Thus, to evaluate the genotoxic potential of silver nanoparticles, in vivo genotoxicity testing (OECD 474, in vivo micronuclei test) was conducted after exposing male and female Sprague-Dawley rats to silver nanoparticles by inhalation for 90 days according to OECD test guideline 413 (Subchronic Inhalation Toxicity: 90 Day Study) with a good laboratory practice system. The rats were exposed to silver nanoparticles (18 nm diameter) at concentrations of $0.7\;{\times}\;10^6$ particles/$cm^3$ (low dose), $1.4\;{\times}\;10^6$ particles/$cm^3$ (middle dose), and $2.9\;{\times}\;10^6$ particles/$cm^3$ (high dose) for 6 hr/day in an inhalation chamber for 90 days. The rats were killed 24 hr after the last administration, then the femurs were removed and the bone marrow collected and evaluated for micronucleus induction. Results: There were no statistically significant differences in the micronucleated polychromatic erythrocytes or in the ratio of polychromatic erythrocytes among the total erythrocytes after silver nanoparticle exposure when compared with the control. Conclusion: The present results suggest that exposure to silver nanoparticles by inhalation for 90 days does not induce genetic toxicity in male and female rat bone marrow in vivo.

• 한국산업보건학회지
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• 제17권3호
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• pp.181-191
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• 2007

With the 2-Butanethiol, which is an unidentified inhalation toxic material, acute inhalation toxicity was tested with SD rats. The $LC_{50}$ was evaluated to be 2,500 ppm (9.22 mg/L) or higher which falls under the criteria of acute toxicity Category 3 (500<$LC_{50}$<2,500 ppm) in the Industrial Safety and Health Act. In the subchronical inhalation toxicity test by 0, 25, 100, and 400 ppm, 6 hours a day, 5 days a week, for 13 weeks repeated exposure, though no death or particular clinical presentation was observed, in the female 25 and 400 ppm group, including weight change, and in each concentration group including 400 ppm, change of feed rate, eye stimulation, motility change in male group, and lesions in blood and blood biochemical were observed. In the internal organs weight, 25, 100, and 400 ppm groups in male and 400 ppm group in female showed significant (p<0.05) changes in kidney, liver, thymus, and lung. In the pathological tissue test, severe cortical tubular hyaline droplets were observed in the male 400 ppm group, and all male rats of 400 ppm group and 2 female individuals showed tubular degeneration/regeneration accompanied with pigmentation, showing that the target organs of inhalation exposure of 2-Butanethiol are spleen, kidney, nasal cavity, and adrenal. Through the tests, the NOEL of 2-Butanethiol was evaluated to be 25 ppm (0.092 mg/L) or less for both male and female.

• Toxicological Research
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• 제23권4호
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• pp.363-371
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• 2007

Isaria sinelairii (IS) was orally administered at doses of 0, 0.04, 0.2, and 1 g/kg/day over a 13-week period. There were no observed clinical signs or deaths related to treatment in all the groups tested. Therefore, the approximate lethal oral dose of I. sinclairii was considered to be higher than 1 g/kg in rats. Throughout the administration periods, no significant changes in diet consumption, ophthalmologic findings, organ weight, clinical pathology (hematology, clinical chemistry, coagulation, and urinalysis) or gross pathology were detected. Minor changes were found in hematological parameters for the 0.04 g/kg/day and 0.2 g/kg/day IS treated groups (triglyceride reductions of $20.1{\sim}46.6%$ and platelet increases), but all changes were within physiological range. Microscopic examination failed to identify any treatment-related histopathologic changes in the organs of the IS-treated rats other than nuclear enlargement (cellular atypia) of the tubular regions in the medulla of the kidney in the high dose group. From these results, one can conclude that the no-observed effect level (NOAEL) of I. sinclairii is less than 0.04 g/kg/day in rats.

• Toxicological Research
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• 제31권1호
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• pp.69-75
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• 2015

The objective of this study was to investigate the toxicological information of freeze-dried powder from Allomyrina dichotoma (A. dichotoma) larvae as a food ingredient. The powder, suspended in distilled water, was administered once daily by oral gavage to four groups of Sprague-Dawley (SD) rats at dose levels of 0 (vehicle control), 250, 850, and 2500 mg/kg/day. After 13 wks of repeated administration, the standard toxicological parameters such as mortality, clinical signs, body weight, food consumption, ophthalmologic examination, clinical pathology, organ weights and macro/microscopic examination were applied for assessment of general toxicity. In addition, serum IgE and histamine levels were determined to evaluate allergenicity. The freeze-dried powder from A. dichotoma larvae did not produce treatment-related changes or findings in any toxicological parameters in either sex of any dosed groups except for slight increases in serum histamine levels at 2500 mg/kg/day. The changes were considered not to be adverse since the magnitude was minimal. In conclusion, the NOAEL (No Observed Adverse Effect Level) of the freeze-dried powder from A. dichotoma larvae was determined to be 2500 mg/kg/day or more in both sexes of SD rats and it is considered a candidate to be edible material.

• Toxicological Research
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• 제31권2호
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• pp.203-211
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• 2015

Trichloroacetonitrile is used as an intermediate in insecticides, pesticides, and dyes. In Korea alone, over 10 tons are used annually. Its oral and dermal toxicity is classified as category 3 according to the globally harmonized system of classification and labelling of chemicals, and it is designated a toxic substance by the Ministry of Environment in Korea. There are no available inhalation toxicity data on trichloroacetonitrile. Thus, the present study performed inhalation tests to provide data for hazard and risk assessments. Sprague-Dawley rats were exposed to trichloroacetonitrile at concentrations of 4, 16, or 64 ppm for 6 hour per day 5 days per week for 13 weeks in a repeated study. As a result, salivation, shortness of breath, and wheezing were observed, and their body weights decreased significantly (p < 0.05) in the 16 and 64 ppm groups. All the rats in 64 ppm group were dead or moribund within 4 weeks of the exposure. Some significant changes were observed in blood hematology and serum biochemistry (e.g., prothrombin time, ratio of albumin and globulin, blood urea nitrogen, and triglycerides), but the values were within normal physiological ranges. The major target organs of trichloroacetonitrile were the nasal cavity, trachea, and lungs. The rats exposed to 16 ppm showed moderate histopathological changes in the transitional epithelium and olfactory epithelium of the nasal cavity. Nasal-associated lymphoid tissue (NALT) and respiratory epithelium were also changed. Respiratory lesions were common in the dead rats that had been exposed to the 64 ppm concentration. The dead animals also showed loss of cilia in the trachea, pneumonitis in the lung, and epithelial hyperplasia in the bronchi and bronchioles. In conclusion, the no-observed-adverse-effect level (NOAEL) was estimated to be 4 ppm. The main target organs of trichloroacetonitrile were the nasal cavity, trachea, and lungs.