Time filter

Source Type

Seo H.-O.,Ministry of Food and Drug Safety | Sohn Y.-T.,Duksung Womens University
Journal of Thermal Analysis and Calorimetry | Year: 2014

DA-6034 is a synthetic flavonoid known to possess anti-inflammatory activity. DA-6034 has been found to exist in six crystal forms, one hydrate form and five solvates. Six crystal forms, one hydrate form and five solvates, of DA-6034 were prepared by recrystallization and they were characterized by DSC, TG and PXRD (Shin and Sohn, J Therm Anal Calorim 115:2457-2461, 2014). This research aimed at investigating the transformation of crystal forms of DA-6034 depending on temperature and relative humidity. Six crystal forms of DA-6034 were kept in different conditions: in 0, 52, and 95 % RH at room temperature to investigate the effect of relative humidity and at RT, 40, and 60 °C to investigate that of temperature. PXRD and TG were used to examine the state of modifications. At 0 % RH Form 2, Form 3, and Form 5 were transformed to amorphous solid and Form 6 was not transformed and Form 4 was transformed to anhydrate. At 52, 95 % RH Form 2, Form 3, Form 4, and Form 6 were transformed to Form 1 (monohydrate) and Form 5 (1.5 H2O, 1/2 acetic acid solvate) was transformed to Form 8 (2 H2O, 0.15 acetic acid solvate). © 2014 Akadémiai Kiadó, Budapest, Hungary. Source

Kudrin A.,Celltrion Inc. | Knezevic I.,World Health Organization | Joung J.,Ministry of Food and Drug Safety | Kang H.-N.,World Health Organization
Biologicals | Year: 2015

The objective of this paper is to provide considerations based on comprehensive case studies important for regulatory evaluation of monoclonal antibodies as similar biotherapeutic products (SBPs) with a special emphasis on clinical aspects. Scientific principles from WHO Guidelines on SBPs were used as a basis for the exercise. Working groups consisted of regulators, manufacturers and academia. The following topics were discussed by the working groups: clinical criteria for biosimilarity, extrapolation approach and the overall regulatory decision making process.In order to determine typical pitfalls in the design of a SBP clinical programme and evaluate the gap of knowledge, amongst different industry and regulatory stakeholders on the appraisal of the data arising from SBP clinical studies, we have presented two fictional but realistic clinical case studies. The first case consists of the fictional development programme for an infliximab SBP candidate. The second case describes clinical studies proposed for a fictional rituximab SBP candidate. In the first scenario a highly similar quality profile has been taken forward into clinical studies whereas there was an important residual difference in functional attributes for the rituximab SBP candidate.These case studies were presented at the WHO implementation workshop for the WHO guidelines on evaluation of similar biotherapeutic products held in Seoul, Republic of Korea, in May 2014. The goal was to illustrate the interpretation of the clinical data arising from studies with SBP candidates and elicit knowledge gaps in clinical assessment. This paper reflects the outcome of the exercise and discussions held in Seoul and offers an analysis of the case studies as a learning opportunity on clinical development and evaluation of SBPs. © 2014 The International Alliance for Biological Standardization. Source

Khan N.,Chosun University | Jeong I.S.,Chosun University | Hwang I.M.,Chosun University | Kim J.S.,Chosun University | And 7 more authors.
Food Chemistry | Year: 2013

This study aimed to validate the analytical method for simultaneous determination of chromium (Cr), molybdenum (Mo), and selenium (Se) in infant formulas available in South Korea. Various digestion methods of dry-ashing, wet-digestion and microwave were evaluated for samples preparation and both inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) were compared for analysis. The analytical techniques were validated by detection limits, precision, accuracy and recovery experiments. Results showed that wet-digestion and microwave methods were giving satisfactory results for sample preparation, while ICP-MS was found more sensitive and effective technique than ICP-OES. The recovery (%) of Se, Mo and Cr by ICP-OES were 40.9, 109.4 and 0, compared to 99.1, 98.7 and 98.4, respectively by ICP-MS. The contents of Cr, Mo and Se in infant formulas by ICP-MS were found in good nutritional values in accordance to nutrient standards for infant formulas CODEX values. © 2013 Elsevier Ltd. All rights reserved. Source

Escudero-Abarca B.I.,North Carolina State University | Suh S.H.,Ministry of Food and Drug Safety | Moore M.D.,North Carolina State University | Dwivedi H.P.,Bio Merieux Inc. | Jaykus L.-A.,North Carolina State University
PLoS ONE | Year: 2014

Human noroviruses (HuNoV) are the leading cause of acute viral gastroenteritis and an important cause of foodborne disease. Despite their public health significance, routine detection of HuNoV in community settings, or food and environmental samples, is limited, and there is a need to develop alternative HuNoV diagnostic reagents to complement existing ones. The purpose of this study was to select and characterize single-stranded (ss)DNA aptamers with binding affinity to HuNoV. The utility of these aptamers was demonstrated in their use for capture and detection of HuNoV in outbreak-derived fecal samples and a representative food matrix. SELEX (Systematic Evolution of Ligands by EXponential enrichment) was used to isolate ssDNA aptamer sequences with broad reactivity to the prototype GII.2 HuNoV strain, Snow Mountain Virus (SMV). Four aptamer candidates (designated 19, 21, 25 and 26) were identified and screened for binding affinity to 14 different virus-like particles (VLPs) corresponding to various GI and GII HuNoV strains using an Enzyme-Linked Aptamer Sorbant Assay (ELASA). Collectively, aptamers 21 and 25 showed affinity to 13 of the 14 VLPs tested, with strongest binding to GII.2 (SMV) and GII.4 VLPs. Aptamer 25 was chosen for further study. Its binding affinity to SMV-VLPs was equivalent to that of a commercial antibody within a range of 1 to 5 μg/ml. Aptamer 25 also showed binding to representative HuNoV strains present in stool specimens obtained from naturally infected individuals. Lastly, an aptamer magnetic capture (AMC) method using aptamer 25 coupled with RT-qPCR was developed for recovery and detection of HuNoV in artificially contaminated lettuce. The capture efficiency of the AMC was 2.5-36% with an assay detection limit of 10 RNA copies per lettuce sample. These ssDNA aptamer candidates show promise as broadly reactive reagents for use in HuNoV capture and detection assays in various sample types. © 2014 Escudero-Abarca et al. Source

Kwon C.H.,Ministry of Food and Drug Safety | Lee Y.D.,Daegu University
Journal of the Korean Society for Applied Biological Chemistry | Year: 2015

Field trials were carried out to investigate the dissipation rates of pesticides as well as to measure the terminal residues in chili peppers. Deltamethrin, dimethomorph, imidacloprid, mepanipyrim, and metalaxyl were applied to chili peppers 15 days prior to harvest. Chili pepper samples were collected at specified intervals and were subjected to residue analysis and dislodgeable residue study. In most cases, initial residue levels were rapidly dissipated with time. The dissipation pattern of pesticide residues fits well to first-order kinetics. Biological half-lives, as calculated from regression curves, of most pesticides were estimated to be <4 days. In the fast growing chili pepper, a dilution effect was considerably involved in the rate of dissipation. As a result, it was possible to predict the terminal residue at harvested crops from the initial residue level and declining curve of pesticides. © 2015, The Korean Society for Applied Biological Chemistry. Source

Discover hidden collaborations