• 한국식품과학회지
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• 제47권6호
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• pp.789-792
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• 2015

본 연구는 국내에서 유통되는 수산물에 대한 방사능 농도 조사 결과를 바탕으로 평상시 수산물의 방사능 농도에 대한 기초자료 생산을 목표로 수행되었으며, 그 과정에서 사고 상황에 맞는 신속한 분석 방법과 최소검출가능농도 설정에 대해 고찰하였다. 국민건강통계의 섭취빈도를 참고로 하여 수산물 시료의 종류를 결정하였고, 전처리 과정을 간소화하여 $^{40}K$, $^{137}Cs$, $^{134}Cs$, $^{131}I$의 방사능 농도를 분석하였다. 그 결과 $^{40}K$는 21.9-3050 Bq/kg의 방사능 농도 범위를 나타내었으며, 인공방사성 핵종인 $^{137}Cs$, $^{134}Cs$, $^{131}I$의 방사능 농도는 최소검출가능농도 이하였다. 따라서, 2013년부터 2015년까지 조사한 국내 유통 수산물에 대해서는 후쿠시마사고의 영향이 없는 것으로 판단할 수 있으며, 선량적인 측면에서 역시 분석한 핵종에 의한 추가적인 방사선 피폭 영향이 없다고 볼 수 있다. 최소검출가능농도의 경우 $^{137}Cs$ 0.140-1.97, $^{134}Cs$ 0.0900-1.89, $^{131}I$ 0.124-1.94 Bq/kg의 범위를 나타내었으며, 시료량 및 $^{40}K$의 농도에 최소검출가능농도 변동을 확인할 수 있었다. 측정시간, $^{40}K$의 농도, 검출기 종류 등의 인자에 따른 최소검출가능농도 설정에 관한 논의가 추후 필요할 것으로 판단된다.

• Journal of Radiation Protection and Research
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• 제47권4호
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• pp.204-213
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• 2022

Background: The accident at the Fukushima Daiichi nuclear power plant increased the level of anxiety related to the radioactive contamination of various foods sourced in Japan. Particularly, after the accident, the detection of artificial radionuclides in locally produced foods raised food safety concerns. In this study, the radioactivity concentrations and annual ingestions of ⁴⁰K and ¹³⁷Cs in food products commonly and frequently consumed by the general public were investigated, and the annual effective dose of each was evaluated. Materials and Methods: The 2016-2018 data from the Radiation Safety Management Report released by the Korea Nuclear Safety Technology Center was referenced for the evaluation of the amounts of ⁴⁰K and ¹³⁷Cs contained in food. Using the food-ingestion survey mentioned above as a reference, we selected 62 foods to include in our radioactivity concentration and dose assessment. We also developed a questionnaire and evaluated the responses from the subjects who answered the questionnaire. Results and Discussion: The radioactivity concentration of ¹³⁷Cs was found to be close to or below the level of minimum detectable activity. Additionally, the annual ingestion of 62 foods was 294.77 kg/yr, the effective doses from ⁴⁰K and ¹³⁷Cs were 136.4 and 0.163 μSv/yr, respectively. Conclusion: Thus, the findings confirmed that the effective dose from ⁴⁰K and ¹³⁷Cs in food tends to be lower than the effective dose limit of 1 mSv/yr suggested by the International Commission on Radiological Protection (ICRP) Publication 60. The questionnaire developed in this study is expected to be useful for estimating the annual effective dose status of Korean adults who consume foods containing ⁴⁰K and ¹³⁷Cs.

• 약학회지
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• 제45권6호
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• pp.650-655
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• 2001

Carvedilol is a nonselective $\beta$-blocking agent with vasodilating properties that are attributed mainly to its blocking activity at $\alpha$$^{1}$-receptors. Carvedilol is used in the treatment of mild to moderate hypertention and angina pectoris and is often used in combination with other drugs. This study was carried out to evaluate the bioequivalence and pharmacokinetics of two carvedilol 25mg tablet formulations according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty healthy volunteers are enrolled and received a single dose (25mg as carvedilol) of each drug in the fasting state, in a randomized 2-way crossover design. After oral administration, blond samples were collected for a period of 30 hours. Plasma concentrations of carvedilol were determined by a rapid and sensitive HPLC method with spectrofluorometric detection. The major pharmacokinetic parameters such as AU $C_{0-}$30hr/, AU $C_{inf}$ , $C_{max}$, $T_{max}$, $t_{1}$2 / Cl/F and V $_{\beta}$//F were calculated. ANOVA test and t-test were utilized for the statistical analysis of each parameter. The results showed that the differences in AU $C_{0-}$30hr/, $C_{max}$ and $T_{max}$ between two were ~5.66, 1.74 and 0.00%, respectively. Minimum detectable differences ($\Delta$) at $\alpha$=0.05 were less than$\pm$ 20% except $T_{max}$ (8.44, 18.36, and 33.86%, respectively). The 90% confidence intervals of all parameters were within $\pm$20% (-10.60~ -0.72, -9.00~12.49 and -19.81~19.81%, respectively). Therefore, it is concluded that the two formulations are bioequivalent for both the extent and the rate of absorption after single dose administration.ation.ion.ion.ation.ion.n.

• 약학회지
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• 제45권2호
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• pp.220-226
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• 2001

A bioequivalence study of Lovastati $n^{TM}$ tablets (Dong Sung Pharmaceutical Co., Korea) to Mevaco $r^{TM}$ tablets (Choong Wae Pharmaceutical Co., Korea) was conducted according to the guidelines (No. 98-56) of Korea Food and Drug Administration (KFDA). Each tablet contained 20 mg of lovastatin. Eighteen healthy Korean male subjects received each formulation at a lovastatin dose of 80 mg (i.e., four tablets) in a 2 $\times$ 2 crossover study. There was a washout period of a week between the dose of the two formulations. Plasma concentrations of lovastatin acid were monitored by a GC/MS method for over a period of 12hr after each administration. The area under the plasma concentration-time curve from time zero to 12hr (AUC) was calculated by a linear trapezoidal method. The maximum plasma drug concentration ( $C_{max}$) and the time to reach $C_{max}$ ( $T_{max}$) were compiled from the plasma drug concentration-time data. Analysis of variance (ANOVA) of these parameters revealed that there are no differences in AUC and $C_{max}$ between the formulations. The apparent differences between the formulations in these parameters were 4.87 and 8.03% for AUC and $C_{max}$, respectively. Minimum detectable differences (%) at $\alpha$=0.1 and 1-$\beta$=0.8 were 17.84 and 15.36% for AUC and $C_{max}$ respectively. The 90% confidence intervals were -15.30~5.56 and -17.02-0.95% for AUC and $C_{max}$, respective1y. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating Mevaco $r^{TM}$ tablets and Dong Sung Lovastati $n^{TM}$ tablets are bioequivalent.ivalent.ent.alent.ent.

• 한국임상약학회지
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• 제8권2호
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• pp.101-106
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• 1998

A bioequivalence study of the Kerola tablets (Dongkwang Pharmaceutical Co., Korea) to the Tarasyn tablets (Roche Co., Korea), formulations of ketorolac trometamine(KTR), was conducted. Sixteen healthy Korean male subjects received each formulation at the dose of 10 mg as KTR in a $2\times2$ crossover study. There was a 1-week washout period between the dose. Plasma concentrations of KTR were monitored by an HPLC method for over a period of 12 hr after each administration. AUC (area under the plasma concentration-time curve) was calculated by the linear trapezoidal method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma drug concentration-time data. Analysis of variance (ANOVA) revealed that there are no differences in AUC, $C_{max}\;and\;T_{max}$ between the formulations. The apparent differences between the formulations in these parameters were all far less than $20\%$ (i.e., 2.31, 8.19 and $0\%$ for AUC, $C_{max}\;and\;T_{max}$, respectively). Minimum detectable differences $(\%)\;at\;\alpha=0.1\;and\;1-\beta=0.8$ were all less than $20\%$ difference in these parameters between the formulations were all over 0.8. The $90\%$ confidence intervals for these parameters were also within $20\%$. These results satisfy the bioequivalence criteria of the Korea Food and Drug Administration (KFDA) guidelines (No. 1998-86). Therefore, these results indicate that the 2 formulations of KTR are bioequivalent and, thus, may be prescribed interchangeably.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2379-2386
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• 2020

This paper presents the results of the first intercomparison exercise performed by the Korea retrospective dosimetry (KREDOS) working group using electron paramagnetic resonance (EPR) spectroscopy. The intercomparison employed the alanine dosimeter, which is commonly used as the standard dosimeter in EPR methods. Four laboratories participated in the dose assessment of blind samples, and one laboratory carried out irradiation of blind samples. Two types of alanine dosimeters (Bruker and Magnettech) with different geometries were used. Both dosimeters were blindly irradiated at three dose levels (0.60, 2.70, and 8.00 Gy) and four samples per dose were distributed to the participating laboratories. Assessments of blind doses by the laboratories were performed using their own measurement protocols. One laboratory did not participate in the measurements of Magnettech alanine dosimeter samples. Intercomparison results were analyzed by calculating the relative bias, E_n value, and z-score. The results reported by participating laboratories were overall satisfactory for doses of 2.70 and 8.00 Gy but were considerably overestimated with a relative bias range of 10-95% for 0.60 Gy, which is lower than the minimum detectable dose (MDD) of the alanine dosimeter. After the first intercomparison, participating laboratories are working to improve their alanine-EPR dosimetry systems through continuous meetings and are preparing a second intercomparison exercise for other materials.

• 한국산업보건학회지
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• 제27권1호
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• pp.38-45
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• 2017

Objectives: Radon may be second only to smoking as a cause of lung cancer. Radon is a colorless, tasteless radioactive gas that is formed via the radioactive decay of radium. Therefore, radon levels can build up based on the amount of radium contained in construction materials such as phospho-gypsum board or when ventilation rates are low. This study provides our findings from evaluation of radon gas at facilities and offices in an industrial complex. Methods: We evaluated the office rooms and processes of 12 manufacturing factories from May 14, 2014 to September 23, 2014. Short-term data were measured by using real-time monitoring detectors(Model 1030, Sun Nuclear Co., USA) indoors in the office buildings. The radon measurements were recorded at 30-minute intervals over approximately 48 hours. The limit of detection of this instrument is $3.7Bq/m^3$. Also, long-term data were measured by using ${\alpha}-track$ radon detectors(${\alpha}-track$, Rn-tech Co., Korea) in the office and factory buildings. Our detectors were exposed for over 90 days, resulting in a minimum detectable concentration of $7.4Bq/m^3$. Detectors were placed 150-220 cm above the floor. Results: Radon concentrations averaged $20.6{\pm}17.0Bq/m^3$($3.7-115.8Bq/m^3$) in the overall area. The monthly mean concentration of radon by building materials were in the order of gypsum>concrete>cement. Radon concentrations were measured using ${\alpha}-track$ in parallel with direct-reading radon detectors and the two metric methods for radon monitoring were compared. A t-test for the two sampling methods showed that there is no difference between the average radon concentrations(p<0.05). Most of the office buildings did not have central air-conditioning, but several rooms had window- or ceiling-mounted units. Employees could also open windows. The first, second and third floors were used mainly for office work. Conclusions: Radon levels measured during this assessment in the office rooms of buildings and processes in factories were well below the ICRP reference level of $1,000Bq/m^3$ for workplaces and also below the lower USEPA residential guideline of $148Bq/m^3$. The range of indoor annual effective dose due to radon exposure for workers working in the office and factory buildings was 0.01 to 1.45 mSv/yr. Construction materials such as phospho-gypsum board, concrete and cement were the main emission sources for workers' exposure.

• Toxicological Research
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• 제24권1호
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• pp.87-91
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• 2008

The present study was conducted to monitor the level of triflumizole residues in fruits (apple and pear) and vegetable (cucumber) samples in order to assess risk posed by the presence of such residues to the consumer. Triflumizole was applied at a recommended dose rate to apple and pear pulps and to a cucumber sample. The samples were collected at harvesting time following several treatments (three and/or four treatments). Triflumizole was extracted with methanol and re-extracted into dichloromethane. The presence of triflumizole was determined by HPLC with UV detection at 238 nm following the cleanup of the extract by open preparative chromatographic column with Florisil. The versatility of this method was evidenced by its excellent linearity (> 0.999) in the concentration range between 0.2 and 4.0 mg/kg. The mean recoveries evaluated from the untreated samples spiked at two different fortification levels. 0.1 and 0.4 mg/kg, and ranged from 87.5${\pm}$0.0 to 93.3${\pm}$2.6 for the tested fruits and vegetable, respectively, and the repeatability (as relative standard deviation) from three repetitive determinations of recoveries were no larger than 6%. The calculated limit of detection was 0.02 mg/kg and the minimum detectable level of 4 ng for triflumizole was easily detected. When triflumizole was sprayed onto the apple trees three times at 50-40-30 and 40-30-21 days prior to harvesting and four times onto the pear trees at 40-30-21-14 days prior to harvesting, the mean residual amounts of 0.05 and 0.06 mg/kg for apples and pears, respectively, were not detected in all of the treatments. When the cucumber sample was fumigated four times at 7, 5, 3 and 1 day prior to harvesting, the mean residual amount was not detectable. Triflumizole can be used safely when sprayed (wettable powder, 30% active ingredient) and fumigated (10%) 4 times at 14 and 1 day prior to harvesting to protect the fruits and vegetable, respectively.

• Journal of Pharmaceutical Investigation
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• 제29권1호
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• pp.67-72
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• 1999

A bioequivalence study of the $Kerola^{\circledR}$ intramuscular injections (Dongkwang Pharmaceutical Co., Korea) to the $Tarasyn^{\circledR}$ intramuscular injections (Roche Co., Korea), formulations of ketorolac tromethamine (KTR), was conducted. Sixteen healthy Korean male subjects were received each formulation at the dose of 30 mg as KTR in a $2{\times}2$ crossover study. There was an one-week washout period between the doses. Plasma concentrations of KTR were monitored by a HPLC method. AUC was calculated by the linear trapezoidal method. $C_{max}$ and $T_{max}$ were compiled from the plasma drug concentration-time data. Analysis of variance (ANOVA) revealed that there are no differences in AUC, $C_{max}$ and $T_{max}$ between the formulations. The differences between the formulations in these parameters were all far less than 20% (i.e., 3.65, 2.59 and 4.35% for AUC, $C_{max}$ and $T_{max}$ respectively). Minimum detectable differences (%) at ${\alpha}=0.1$ and $1-{\beta}=0.8$ were 12.87, 13.44, 20.62%, for AUC, $C_{max}$ and $T_{max}$, respectively. The 90% confidence intervals for these parameters were also within 20%. These results satisfy the bioequivalence criteria of the Korea Food and Drug Administration (KFDA) guidelines (No. 1998-86). Therefore, these results indicate that the two formulations of KTR are bioequivalent.

• Biomolecules & Therapeutics
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• 제6권4호
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• pp.423-428
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• 1998

Aceclofenac is an orally effective non-steroidal anti-inflammatory agent of the phenylacetic acid derivative. Bioequivalence study of two aceclofenac preparations, the test drug (Senafe $n_{R}$: Daewon Phar-maceutical Company) and the reference drug (Airta $l_{R}$: Daewoong Pharmaceutical Company), was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Sixteen healthy male volunteers, 24$\pm$4 years old and 63.9$\pm$6.9 kg of body weight in average, were divided randomly into two groups and administered the drug orally at the dose of 100 mg as aceclofenac in a 2$\times$2 crossover study. Plasma concentrations of aceclofenac were monitored by HPLC method for 12 hr after administration. AU $Co_{-12h}$ (area under the plasma concentration-time curve from initial to 12 hr) was calculated by the linear trapezoidal method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{msx}$) were compiled directly from the plasma drug concentration-time data. Student's t-test indicated no significant differences between the formulations in these parameters. Analysis of variance (ANOVA) revealed that there are no differences in AU $Co_{12h}$, $C_{max}$ and $T_{max}$ between the formulations. The apparent differences between the formulations were far less than 20% (e.g., 0.25, 0.01 and 7.32 for AU $Co_{-12h}$, $C_{max}$. and $T_{max}$, respectively). Minimum detectable differences (%) between the formulations at $\alpha$=0.05 and 1-$\beta$=0.8 were less than 20% (e.g., 14.65, 12.47 and 15.46 for AU $Co_{-l2h}$, $C_{max}$ and $T_{max}$, respectively). The 90% confidence intervals for these parameters were also within $\pm$ 20% (e.g.,-10.19~10.68, -8.87~8.89 and -3.69~ 18.33 for AU $Co_{-12h}$, $C_{msx}$ and $T_{max}$, respectively). These results satisfy the bioequivalence criteria of KFDA guidelines, indicating that two formulations of aceclofenac are bioequivalent.quivalent.ivalent.ent.t.ent.