• Analytical Science and Technology
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• v.34 no.1
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• pp.1-8
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• 2021

An analytical method was developed and optimized for the quantification of a plant growth regulator, 2,6-diisopropylnaphthalene (2,6-DIPN), in agricultural products using gas chromatography-tandem mass spectrometry. The samples were extracted, partitioned, and were purified using a Florisil® cartridge. To validate the analytical method, its specificity, linearity, limit of detection (LOD) and limit of quantification (LOQ) of the instrument, LOQ of the analytical method (MLOQ), accuracy, and repeatability were considered. The method displayed excellent results during validation, and is suitable for the determination and quantification of the low residual levels of the analyte in the agricultural samples. All of the results with the optimized method were satisfactory and within the criteria ranges requested in the Codex Alimentarius Commission guidelines and the Ministry of Food and Drug Safety guidelines for pesticide residue analysis. The developed method is simple and accurate and can be used as a basis for safety management of 2,6-DIPN.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.246-252
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• 2020

BACKGROUND: Pesticides are broadly used to control weeds and pests, and the residues remaining in crops are managed in accordance with the MRLs (maximum residue limits). Therefore, an analytical method is required to quantify the residues, and we conducted a series of analyses to select and validate the quick and simple analytical method for tolpyralate in five agricultural products using QuEChERS (quick, easy, cheap, effective, rugged and safe) method and LC-MS/MS (liquid chromatography-tandem mass spectrometry). METHODS AND RESULTS: The agricultural samples were extracted with acetonitrile followed by addition of anhydrous magnesium sulfate, sodium chloride, disodium hydrogencitrate sesquihydrate and trisodium citrate dihydrate. After shaking and centrifugation, purification was performed with d-SPE (dispersive-solid phase extraction) sorbents. To validate the optimized method, its selectivity, linearity, LOD (limit of detection), LOQ (limit of quantitation), accuracy, repeatability, and reproducibility from the inter-laboratory analyses were considered. LOQ of the analytical method was 0.01 mg/kg at five agricultural products and the linearity of matrix-matched calibration were good at seven concentration levels, from 0.0025 to 0.25 mg/L (R²≥0.9980). Mean recoveries at three spiking levels (n=5) were in the range of 85.2~112.4% with associated relative standard deviation values less than 6.2%, and the coefficient of variation between the two laboratories was also below 13%. All optimized results were validated according to the criteria ranges requested in the Codex Alimentarius Commission (CAC) and Ministry of Food and Drug Safety (MFDS) guidelines. CONCLUSION: In conclusion, we suggest that the selected and validated method could serve as a basic data for detecting tolpyralate residue in imported and domestic agricultural products.

• Korean Journal of Environmental Agriculture
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• v.39 no.2
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• pp.130-137
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• 2020

BACKGROUND: Mefentrifluconazole and triticonazole are the triazole fungicides. The maximum residue levels for agricultural products need to be set up. Therefore, development of the official analytical method for determination of mefentrifluconazole and triticonazole residues from agricultural crops was necessary due to safety management, and then a simultaneous analytical method was developed for the determination of mefentrifluconazole and triticonazole in agricultural crops. METHODS AND RESULTS: Samples were extracted using acetonitrile and purified using dispersive solid phase extraction, and then detected with liquid chromatograph-tandem mass spectrometry (LC-MS/MS). Matrix-matched calibration curves (0.0025-0.25 ㎍/mL) were linear into a sample extract with r²>0.99. For validation, the recovery test was carried out at three fortification levels (LOQ, 10 LOQ and 50 LOQ) from agricultural samples. The results for mefentrifluconazole and triticonazole ranged between 92.3 to 115.3% and 91.4 to 108.5%, respectively and RSD (relative standard deviation) values were also below 6.0%. Furthermore, inter-laboratory was conducted to validate the method. CONCLUSION: All values were corresponded with the criteria ranges requested by both the CODEX (CAC/GL 40-1993, 2003) and MFDS guidelines (2016). Therefore, the proposed method can be used as an official analytical method for determination of mefentrifluconazole and triticonazole (triazole fungicides) in the Republic of Korea.

• Korean Journal of Clinical Pharmacy
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• v.19 no.1
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• pp.50-60
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• 2009

Highly variable drugs (within-subject variability greater than 30%) have been difficult to meet current regulatory acceptance criteria using a reasonable number of study subjects. In this study, we reviewed previous studies presenting alternative approaches for bioequivalence evaluation of highly variable drugs, and focused on an approach for widening the bioequivalence acceptance limits using within-subject variability. We discussed the suggested five solutions for highly variable drug including the deletion of $C_{max}$ of the bioequivalence criteria, direct expansion of bioequivalence limit, multiple dose studies in steady state, bioequivalence assessment on the metabolite, add-on study, and widening the bioequivalence acceptance limits based on reference variability. The methods for widening of bioequivalence limits based on reference variability are scaled average bioequivalence containing within-subject variability on reference drug (${\sigma}_{WR}$), population bioequivalence derived from total variability on reference drug (${\sigma}_{TR}$) and test drug (${\sigma}_{TT}$), and individual bioequivalence derived from subject by formulation interaction variability (${\sigma}_D$) and within subject variability on reference drug (${\sigma}_{WR}$) and test drug (${\sigma}_{TR}$). To apply these methods, the switching variability (${\sigma}_0$) will have to be set by the regulatory authorities. The proposals of bioequivalence evaluation approach for the highly variable in Korea are presented for both of new drug and reevaluation drug.

• Tuberculosis and Respiratory Diseases
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• v.80 no.2
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• pp.136-142
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• 2017

Assessing response to therapy allows for prospective end point evaluation in clinical trials and serves as a guide to clinicians for making decisions. Recent prospective and randomized trials suggest the development of imaging techniques and introduction of new anti-cancer drugs. However, the revision of methods, or proposal of new methods to evaluate chemotherapeutic response, is not enough. This paper discusses the characteristics of the Response Evaluation Criteria In Solid Tumor (RECIST) version 1.1 suggested in 2009 and used widely by experts. It also contains information about possible dilemmas arising from the application of response assessment by the latest version of the response evaluation method, or recently introduced chemotherapeutic agents. Further data reveals the problems and limitations caused by applying the existing RECIST criteria to anti-cancer immune therapy, and the application of a new technique, immune related response criteria, for the response assessment of immune therapy. Lastly, the paper includes a newly developing response evaluation method and suggests its developmental direction.

• YAKHAK HOEJI
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• v.55 no.4
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• pp.284-288
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• 2011

The test method for biologics of lot release system is based on 'Test procedure and specification for biological products,' generally, thimerosal content is measured by chemical analysis using O.D. In this study, the comparative analysis was carried out using the gold amalgamation method for thimerosal content was compared to the existing methods, which are described above. The gold amalgamation method, which uses atomic absorption spectrophotometry, was meets all the method validation acceptance criteria. It is considered to be proper as the assay and identification test for thimerosal. In this study, the comparative analysis was performed three times. As a result, gold amalgamation method is more convenient and easy to perform as this assay doesn't have pre-treatment procedure. Also this assay showed good precision and reproducibility compared to the conventional method. Therefore, it is appropriate to alternate the assay method of thimerosal from the conventional chemical analysis to gold amalgamation method to improve the credibility of lot release system and the quality control of biologics, by standardizing test method.

• Journal of Pharmacopuncture
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• v.24 no.2
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• pp.59-67
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• 2021

Objectives: We aimed to compare the external herbal dispensary (EHD) evaluation criteria for pharmacopuncture and the Korea Good Manufacturing Practice (KGMP) sterile medicine standards to contribute to the establishment of quality control criteria for pharmacopuncture. Methods: We obtained the KGMP standards from the Ministry of Food and Drug Safety and the pharmacopuncture certification criteria from the Ministry of Health and Welfare of South Korea. The EHD evaluation items were classified into three categories: facilities, quality control, and validation. The evaluation items were compared with the KGMP sterile medicine criteria to determine their conformance with each other, followed by a discussion among the committee of six experts and their consensus to suggest the items to complement the EHD evaluation criteria. Results: Among the KGMP sterile medicine criteria, 44 were related to the management of the facilities, and 32 pharmacopuncture evaluation items corresponded to these KGMP items (66.7%). Fifty-eight KGMP criteria were related to quality management, and 42 pharmacopuncture evaluation items corresponded to these KGMP items (72.4%). Twentyfive KGMP sterile medicine criteria were related to validation, and 11 pharmacopuncture evaluation items corresponded to these KGMP items (44.0%). Sixteen items under the pharmacopuncture EHD criteria corresponded to the KGMP sterile medicine criteria based on the consent of the experts. Among these, 4 were related to facility management, 6 were related to quality control, and 6 were related to validation. Conclusion: For the safety and quality control of pharmacopuncture, there is a need to select the criteria for the mandatory items among the proposed pharmacopuncture-EHD criteria laws and systems to ensure that the pharmacopuncture materials are produced under the pharmacopuncture-EHD in compliance with the relevant requirements. More studies are needed to secure the safety level of pharmacopuncture materials corresponding to that of conventional medicine.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6055-6059
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• 2015

Background: Medication policy development in Thailand is continually promoting rational drug use. Letrozole, an endocrine therapy drug, is usually prescribed for post-menopausal status early and advanced stage breast cancer. After Ministry of Public Health announced Letrozole as compulsory licensed drug in 2009, more breast cancer patients can access to this drug at low cost especially those within universal coverage schemes. To ensure that Letrozole is rationally prescribed, the drug utilization study was conducted. Objectives: The aim of this study was to describe the appropriate use of Letrozole in breast cancer and the relationship between appropriate use and health benefit schemes. Materials and Methods: A retrospective study to evaluate use of Letrozole in breast cancer patients was performed for six months between January - June 2010 in seven regional cancer hospitals, Thailand. All prescriptions of Letrozole were identified from pharmacy dispensing databases and prescription papers. A medical record review was also performed to evaluate appropriate use referring to the drug use evaluation criteria. The approved criterion of this study was referred from the guideline of Thai National Formulary version 2010. Results: There were 681 prescriptions of Letrozole for 254 breast cancer patients with an average age of $58.6{\pm}10.0years$. The patients in universal coverage scheme (UCS), civil servant medication benefit scheme (CSMBS) and social security scheme (SSS) were 77.7%, 18.5% and 8.7% respectively. 10.6% were prescribed Letrozole for the first time. Letrozole were prescribed by oncologists (82.8%). The average number of tablets per prescription was $58{\pm}10$. Calcium supplements were prescribed concomitant with Letrozole for 19.4%. To assess drug use evaluation criteria, 45 prescriptions were excluded because of uncompleted clinical data, 636 prescriptions were evaluated. The study showed 86 prescriptions (13.5%) with inappropriate use including 6 (0.9%) not prescribed for estrogen receptor (ER) and/or progesterone receptor (PR) positive, 31 (4.9%) not prescribed for post-menopausal and 49 (7.7%) not prescribed for an appropriate duration. Appropriate use percentages in different health benefit schemes were similar, 85.7% of CSMBS, 86.4% of SSS and 86.7% of UCS. The relationship between health benefit scheme and appropriate use of Letrozole was not significantly different, ${\chi}^2$ (2, N = 636) = 0.081, p > 0.05. Conclusions: The study showed inappropriate use in breast cancer patients because of non-compliance with duration, menopausal status and hormone receptor requirements. To prescribe appropriate indication did not referred to the appropriate practice along the treatment. Drug use evaluation proved very useful for detecting the sign of inappropriate use and allows immediate feedback to the stakeholder for developing medication policy in the future. Importantly, there was no significantly difference in appropriate use of Letrozole across health benefit schemes.

• Toxicological Research
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• v.28 no.2
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• pp.73-79
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• 2012

While the ability to develop nanomaterials and incorporate them into products is advancing rapidly worldwide, understanding of the potential health safety effects of nanomaterials has proceeded at a much slower pace. Since 2008, Korea Food and Drug Administration (KFDA) started an investigation to prepare "Strategic Action Plan" to evaluate safety and nano risk management associated with foods, drugs, medical devices and cosmetics using nano-scale materials. Although there are some studies related to potential risk of nanomaterials, physical-chemical characterization of nanomaterials is not clear yet and these do not offer enough information due to their limitations. Their uncertainties make it impossible to determine whether nanomaterials are actually hazardous to human. According to the above mention, we have some problems to conduct the human exposure risk assessment currently. On the other hand, uncertainty about safety may lead to polarized public debate and to businesses unwillingness for further nanotechnology investigation. Therefore, the criteria and methods to assess possible adverse effects of nanomaterials have been vigorously taken into consideration by many international organizations: the World Health Organization, the Organization for Economic and Commercial Development and the European Commission. The object of this study was to develop risk assessment principles for safety management of future nanoproducts and also to identify areas of research to strengthen risk assessment for nanomaterials. The research roadmaps which were proposed in this study will be helpful to fill up the current gaps in knowledge relevant nano risk assessment.

• Journal of Biomedical Engineering Research
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• v.32 no.2
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• pp.151-157
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• 2011

Tattooing is a performance for decorative and cosmetic marking by placing permanent ink into the skin. As the cultural meaning of tattoo in Korea is changing, the tattoo machines are widely spread n permanent cosmetic market. Though the use of the tattoo machine was increased, the evaluation standards of tattoo machine were not existed. Korea Food and Drug Association regulated the electrical and mechanical safety standards which were founded on the IEC 601-1 second edition. Also they regulated he biological safety standards which were derived from the ISO 10993 series, however, these general valuations of common medical device were insufficient for evaluating tattoo machine. We developed the standards of tattoo machine for safety and performance evaluation for tattoo machine by preliminary hazard analysis in ISO 14971. The evaluation criteria of tattoo machines are focused on the mechanical invasion. We suggested the additional evaluation items of the needle speed, length, vibration with general valuation criteria of common medical device. We anticipate that this research may be a primary stage to figure a standard regulation and evaluation for tattoo machine.