• Natural Product Sciences
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• v.5 no.2
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• pp.107-111
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• 1999

To investigate less toxic antiviral agents from Basidiomycetes, EA, the water soluble substance, was isolated from the carpophores of Elfvingia applanata (pers.) Karst. Anti-varicella zoster virus (Oka strain; anti-VZV/Oka) activity of EA was examined in MRC-5 cells by plaque reduction assay in vitro. And the combined antiviral effects of EA with nucleoside anti-VZV agents, acyclovir and vidarabine, were examined on the multiplication of VZV/Oka. EA exhibited a concentration-dependent reduction in the plaque formation of VZV/Oka with a 50% effective concentration $(EC_{50})$ of $464.14\;{\mu}g/ml$. The results of combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combination of EA with acyclovir showed more potent synergism with CI values of $0.18{\sim}0.62$ for $50{\sim}90%$ effective levels than that of EA with vidarabine with CI values of $0.67{\sim}1.04$.

• Korean Journal of Pharmacognosy
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• v.30 no.3
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• pp.244-249
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• 1999

In order to find less toxic antiviral agents from Basidiomycetes, EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata(Pers.) Karst. Antiviral activity of EA against vesicular stomatitis virus [Indiana serotype, VSV(IND)] was examined in Vero cells using plaque reduction assay in vitro. And the combined antiviral effects of EA with interferon (IFN) alpha or gamma were examined on the multiplication of VSV(IND). EA caused a concentration-dependent reduction in the plaque formation of VSV(IND) with 50% effective concentration $(EC_{50})$ of $104.02\;{\mu}g/ml$. The results of combination assay were evaluated by the combination index (CI) that was analysed by the multiple drug effect analysis. All cases of the combination of EA with IFN alpha or IFN gamma showed potent synergism with CI values of $0.38{\sim}0.52$ for $50{\sim}90%$ effective levels.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.443-446
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• 2010

HPLC analysis of a commercial herb drink marketed as a functional food revealed to contain an unauthorized substance similar to sildenafil, the active ingredient of the prescription drug Viagra$^{(R)}$ approved for the treatment of male erectile dysfunction. In order to identify the illegal additive, the herb drink was extracted with methylene chloride, and the extract was purified further using semipreparative HPLC. The chemical structure of the isolated substance was elucidated based on IR, LC/MS-ESI, and NMR spectroscopy, which showed the characteristics similar to sildenafil with minor modification. The only difference was the substitution of the methylpiperazine moiety of sildenafil to the hydroxyethylpiperazine group of the illegal additive.

• YAKHAK HOEJI
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• v.55 no.5
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• pp.426-431
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• 2011

This study was performed to investigate the current regulatory guidances of safety and efficacy evaluation for the development and approval of stereoisomeric drugs in US, EU, Canada and Japan. The important categories for the development of stereoisomeric drugs are classified as 1) development of a single enantiomer as a new active substance 2) development of a racemate as a new active substance 3) development of a new single enantiomer from an approved racemate. The regulatory documents adopted in major countries for the safety and efficacy evaluation of stereoisomeric drugs were investigated with the focus on three major categories mentioned above. For the regulatory approval of stereoisomeric drugs in Korea, it is expected that the investigated results obtained in this study will be useful for the basic materials to ensure the safety and efficacy of stereoisomeric drugs as well as the stereochemical issues in chiral drug development in domestic pharmaceutical company.

• Journal of Pharmaceutical Investigation
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• v.27 no.3
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• pp.219-223
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• 1997

Terfenadine, antihistaminic drug, is poorly soluble in water. The purpose of this study is to investigate the possibility of using $terfenadine-{\beta}-cyclodextrin$ inclusion compound, instead of terfenadine, as the active substance of solid dosage form by improving the solubility, dissolution and anti-histaminic activity of terfenadine. The solubility and binding characteristics of $terfenadine-{\beta}-cyclodextrin$ complex in pH $1.2{\sim}6.8$ were investigated. Furthermore, the preparing method of $terfenadine-{\beta}-\;cyclodextrin$ inclusion compound was setting up and its physico-chemical characteristics such as DSC curve, solubility, dissolution and anti-histaminic activity were investigated. In conclusion, the solubility of terfenadine was increasing ${\beta}-cyclodextrin$ and with the decreasing pH. $Terfenadine-{\beta}-cyclodextrin$ inclusion compound, whose yield is almost 100%, was prepared by neutralization method. This inclusion compound was 200-times as soluble as terfenadine in pH 1.2-6.8. In addition, it had the faster dissolution and anti-histaminic activity than terfenadine. Therefore, it is used to the active substance of solid dosage form such as tablet and capsule in stead of terfenadine.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.1 no.1
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• pp.130-147
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• 1990

This study intended to investigate the characteristics of adolescent drug user in Korea. A questionnaire on adolescent drug use was administered to 1st or 2nd grade 898 students (465 males, 433 females) from 9 senior high schools in Seoul area. The extent of current using six representative drugs such as cigarettes, alcohol, chemical substance inducing hallucination(e,g., thinner, bond etc.), psychostimulant, hypnotic and minor tranqulizer was self-reported. Also their psychological distress, self-concept and individual-related variables such as academic grade, deviant behavior, drug-using peers, the perceived availability of drugs, the degree of family discipline, and the perceived parents' attitude for drinking and smoking were surveyed. Subjects were grouped into six(male) or five(female) subgroups (nonuser, simple experiencer, one kind of drug user, two kinds of drugs user, three kinds of drugs user(male only), minor tranqulizer user) to their extent of drug use. Then ANOVA procedure performed for group comparison of their psychological distress, self-concept and individual-related variables. The results showed that the most popular drugs among adolescents in Korea were cigarettes and alcohol. Minor tranqulizer was used by about 2.8% of male and 7.41% of female subjects. In general abusers showed lower academic grade, more deviant experiences, having more drug-using peers, higher degree of psychological distress, and lower postitive self-concept than nonuser group. According to the results of discriminant analysis, hostility and deviant behavior were reliable predictive variables that distinguished abuser group from nonuser group among the associated variables in this study. These results suggest that some common factors affect drug use of Korean high school students : high school students who have many common risk factors could be abusers more easily. These findings supported risk factor theory that the extent of drug use of adolescents might be associated with general maladjustment in everyday life.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.838-843
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• 2005

Bacterial suspension test was used to establish Standardization Test Method to investigate bactericidal activity of disinfectant/sanitizer product. Using acceptable verification methodology, test substance showing 5 log or higher reduction in viable count against Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 6538, representing Gram-negative and -positive bacteria, respectively, under test conditions for $5\;min{\pm}10\;sec\;at\;20{\pm}1^{\circ}C$ was considered to have sanitizing capability. All disinfectant/sanitizer products tested under manufacturer's recommended in-use condition gave good reduction values against major food-poisoning bacteria. This standardized method was valuable for evaluating efficacy of disinfectants/sanitizers and could be used as Standardization Test Method for assessing bactericidal activity

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7549-7554
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• 2015

The aim of this study was to develop gastric retentive bi-layered tablet using floating drug delivery technique. Metformin was selected as a model drug due to its narrow absorption window as well as very highly water solubility. These properties of metformin led to be difficult controlling the drug release. The bi-layered tablet was prepared with bi-layered compression machine to minimize interference between floating part and controlling part. The tablet weight, appearance and hardness were evaluated after compression process. The times of 'time to floating' and 'Floating duration' were tested for floating ability and drug release study was also carried out to understand drug release behavior. Furthermore, the drug release of bi-layered tablet was compared with marketed metformin tablet with sustained release pattern (Glucopharge XR$^{(R)}$).The floating ability and drug release behaviors were well controlled by changing amounts of $NaHCO_3$ (floating substance) and hydroxypropyl methylcellulose (HPMC; release control material). Bi-layered tablet had 13s of time to float, over 10h of floating duration and very similar drug release behavior compared with Glucopharge XR$^{(R)}$($f_2$: 89.6). Consequently, the bi-layered tablet with floating ability was successfully prepared and these properties can maximize the efficacy of metformin.

• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.415-421
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• 2016

The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower $IC_{50}$ values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.

• Toxicological Research
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• v.14 no.4
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• pp.547-555
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• 1998

The subchronic toxicity of a combined preparation of ticlopidine and ginkgo biloba extract (EGb 761) mixed in a ratio of 10: 4 was examined in male and female Sprague-Dawley rats. Rats were treated with the test substance at a dose of 52 mg/kg, 156 mg/kg, or 467 mg/kg intragastrically for 30 consecutive days. Control rats were treated with vehicle only. Each group consisted of 10 rats. No death or abnormal clinical signs were observed throughout the administration period. A transient decrease in body weight gain and food intake was observed in the rats treated with the high dose (467 mg/kg), which was recovered to normal in a week. There were no drug-related differences in urinalysis and hematological results. A significant increase in serum total cholesterol and total protein was observed in both sexes of the rats treated with a dose of 467 mg/kg daily, but all the other values obtained in serum chemistry appeared to be within normal range. A dose dependent increase in liver weight was observed in both male and female rats. Relative kidney weight was also increased in the high dose groups. There was no gross pathological finding at terminal sacrifice. Microscopic histopathological examination did not show any lesion in terms of correlation with administration of the test substance. The results suggest that under the conditions employed in this study no observable effect level (NOEL) of the test substance be 52 mg/kg/day.