• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.313-321
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• 1997

Ion exchange resin complexes of famotidine have been prepared by the reaction of famotidine solution with activated ion exchange resins. Complex formation efficiency between famotidine and ion exchange resin was about $80{\sim}90%$ in average, calculated by HPLC determination. Drug release characteristics from the resin complexes were evaluated by the modified percolation method. Famotidine release was dependent on the type of ion exchange resins. In the case of weakly acidic resin complexes, the cumulative released amount of famotidine was more than 90% for 1hr in pH 1.2 buffer solution. However, in the case of strongly acidic resin complexes, it was less than 5% for 3hr in the same medium. Strongly acidic resins revealed some advantages over weakly, acidic resins for overcoming instability of famotidine in gastric juice. In addition, strongly acidic resin complexes showed controlled release of famotidine in pH 6.8 buffer solution, showing the result of about 60 to 70% of drug release for 5hr. After oral administrations of famotidine-resin complexes to rats as dose of 40 mg equivalent/kg, the pharmacokinetic parameters of famotidine were obtained by model independent analysis and compared with those of famotidine solution or suspension. $C_{max}$ of famotidine-resin complex was lower than that of famotidine solution or suspension. MRT, MAT, and MDT of the complexes were greater than those of famotidine solution or suspension. From these results, it was expected that famotidine was released slowly from the complexes and absorbed continuously into systemic circulation. It was recognized that drug release from the complexes was the rate-limiting step in drug absorption, since there were close correlations between in vitro drug release and in vivo pharmacokinetic parameters.

• The Korean Journal of Pain
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• v.30 no.1
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• pp.18-33
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• 2017

As the treatment of chronic non-cancer pain gradually increases, clinicians have more opportunities to encounter opioid prescription. However, guidelines for prescribing opioids for chronic non-cancer pain have never been published in Korea. The present guidelines were prepared by reviewing various research data. In cases in which the data were insufficient, recommendations were presented following discussion among experts affiliated with the Opioids Research Group in the Korean Pain Society. The present guidelines may need to be continuously revised and amended as more clinical evidence is acquired.

• YAKHAK HOEJI
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• v.49 no.4
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• pp.323-329
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• 2005

Antimicrobial peptides are evolutionary ancient weapons for animal and plant species to depend themselves against infectious microbes. In the present study, we investigated if an antimicrobial peptide was produced from Coptidis Rhizoma. For the determination, protein substance from the medicinal plant was isolated by various preparations. Among the preparations, the protein portion dissolved in phosphate-buffered saline solution (CRP-DS) that contained the most amount of protein $(90\%)$ resulted in maximal inhibition of Candida albicans which causes local and systemic infections. Analyses by gel-electrophoresis and gel-permeation chromatography showed the CRP-DS formed a single band of approximately 11.8 KDa as molecular size. Antifungal activity of the CRP-DS was almost equivalent to antifungal activity by fluconazole, resulting in MIC (minimal inhibitory concentration) of approximately $50{\mu}g/ml$. The antifungal activity was a dose-dependent. The antifungal activity appeared to be inactivated by heat-treatment and ionic strength, respectively. In a murine model, the CRP-DS enhanced resistance of mice against disseminated candidiasis. The HPLC analysis demonstrated maximum $4\%$ of berberine as residual content in the CRP-DS preparation resulted in no influence on the antifungal activity. In addition, protein portion isolated from Phellodendri Cortex producing the alkaloid component like Coptidis Rhizoma had no such anticandidal effect. These results indicate that the protein substance from Coptidis Rhizoma was responsible for the antifungal activity.

• YAKHAK HOEJI
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• v.38 no.2
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• pp.140-148
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• 1994

${\beta}-Lactamase$ stability, chemotherapeutic activity, and pharmacokinetics of 7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl]thiocarbonylthiomethyl-3-cephem-4-carboxylic acid(CEN1), 7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyrimidyl)piperazinyl]thiocarbonylthiomethyl-3-cephem-4-carboxylic acid(CEN2), pivaloyloxymethyl-7-[(Z)-2-(2-aminothizaole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl]thiocarbonyl-thiomethyl-3-cephem-4-carboxylate(CEN1P), and pivaloyloxymethyl-7-{(Z)--2-(2-aminothizaole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl]thiocarbonyl-thiomethyl-3-cephem-4-carboxylate(CEN2P) were examined. CEN1, CEN2, CEN1P, and CEN2P were very stable to the ${\beta}-lactamase$ obtained from three strains(Enterobacter cloacae P99, Escherichia coli TEM, and Citrobacter freundii). Chemotherapeutic activities$(ED_{50})$ of CEN2 and CEN2P against experimental systemic infections due to Streptococcus pyogenes 77A and Escherichia coli 078 were superior to those of CEN1 and CEN1P, respectively. The $ED_{50}$ values of CEN1, CEN2 were 5.82 mg/kg, 0.89 mg/kg(s.c., S. pyogenes 77A) while those of CEN1P, CEN2P were 14.56mg/kg, 6.40mg/kg(p.o., S. pyogenes 77A), respectively. The pharmacokinetics of CEN1, CEN2, CEN1P, and CEN2P were investigated in mice and rats. In mice, peak blood levels of $1.25\;{\mu}g/ml$ were recorded within 20 min after oral administration of a single dose equivalent to 40 mg/kg CEN1P. Cmax of CEN1P was much higher than that of CEN1 in mice and rats. Oral absorption of CEN2P was much higher than that of CEN2.

• Advances in Traditional Medicine
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• v.5 no.2
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• pp.92-99
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• 2005

Asclepias curassavica. Linn, an erect, simple (or) much branched perennial herb with a somewhat woody base, belonging to the family Asclepiadaceae. It has been reported to have multiple pharmacological effect of anti-inflammatory, cardiotonic, anticancer, anthelmintic and to treat piles and gonorrhoea. It is to be expected that several activities might be related to a possible antioxidant action from this plant. The hydro alcoholic extract of Asclepias curassavica was tested in vitro for its antioxidant activities, such as DPPH radical, nitric oxide radical, superoxide anion radical, lipid peroxidation assay, hydroxyl radical, reducing power, and total phenol content. The extract exhibited scavenging potential with $IC_{50}$ value of $8.7\;{\mu}g/ml,\;198.4\;{\mu}g/ml\;and\;21.7\;{\mu}g/ml$ for DPPH, nitric oxide and superoxide anion radicals. The values were found to higher than those of Vitamin-C, rutin, and curcumin, as standards. The extract showed 50% protection at the dose of $134.2\;{\mu}g/ml\;and\;41.4\;{\mu}g/ml$ in lipid peroxidation as well as deoxyribose degradation, those values more to that of standard, vitamin E $(IC50\;values,\;119.2\;{\mu}g/ml\;and\;32.5\;{\mu}g/ml,\;respectively)$. The reducing power of the extract depends on the concentration and amount of extract. Since a significant amount of polyphenol could be detected by the equivalent to $0.0495\;{\mu}g$ of pyrocatechol from 1 mg of extract. It can be concluded that hydro alcoholic extract of aerial part of Asclepias curassavica could be considered as potent antioxidant, which makes it suitable for the prevention of human disease.

• Journal of Radiation Protection and Research
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• v.23 no.4
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• pp.243-249
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• 1998

The methodology for justification and optimization of the countermeasures related with contamination management of milk was designed based on the cost and benefit analysis. The application results were discussed for the deposition on August 15, when pasture is fully developed in Korean agricultural conditions. A dynamic food chain model DYNACON was used to estimate the time-dependent radioactivity of milk after the deposition. The considered countermeasures are (1) the ban of milk consumption (2) the substitution of clean fodder, which are effective in reducing the ingestion dose as well as simple and easy to carry out in the first year after the deposition. The total costs of the countermeasures were quantitatively estimated in terms of cost equivalent of doses and monetary costs. It is obvious that a fast reaction after the deposition is an important factor in cost effectiveness of the countermeasures. In most cases, the substitution of clean fodder was more effective countermeasure than the ban of consumption. A fast reaction after the deposition made longer justifiable/optimal duration of the countermeasure.

• Korean Journal of Clinical Pharmacy
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• v.13 no.1
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• pp.13-17
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• 2003

This study was carried out to compare the bioavailability of $Ceclex^{(R)}$ SR TAB (test drug, cefaclor 375 mg/Tablet) with that of Ceclor $MR^{(R)}$ SR IAB (reference drug) and to estimate the pharmacokinetic parameters of cefaclor in healthy Korean volunteers. The bioavailability was examined on 24 healthy volunteers who received a single dose (375 mg) of each drug in the fasting state in a randomized balanced 2-way crossover design. After dosing, blood samples were collected for a period of 7 hours. Plasma concentrations of cefaclor were determined using HPLC with UV detection. The pharmacokinetic parameters $(AUC_{0-7h},\;C_{max},\;T_{max},\;AUC_{inf},\;K_e,\;t_{1/2},\;V_d/F,\;and\;CL/F)$ were calculated with non-compartmental pharmacokinetic analysis. The ANOVA test was utilized for the statistical analysis of the $T_{max}$, log-transformed $AUC_{0-7h$}$, log-transformed $C_{max},\;t_{1/2},\;V_d/F$, and $CL/F$. The ratios of geometric means of $AUC_{0-7h}\;and\;C_{max}$ between test drug End reference drug were $95.67\%\;(8.55\;vs\;8.18{\mu}g{\cdot}hr/ml)\;and\;103.86\%\;(2.85\;vs\;2.96{\mu}g/ml)$, respectively. The $T_{max}$ of test drug and reference drug was $2.56\pm0.15\;and\;2.23\pm0.13\;hrs,\;respectively.\;The\;90\%$ confidence intervals of mean difference of logarithmic transformed $AUC_{0-7h}\;and\;C_{max}$ were log0.90-log1.04 and log0.91-log1.13, respectively. It shows that the bioavailability of test drug is equivalent with that of reference drug.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.429-432
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• 2000

Chitosan scaffold is widely applied to drug delivery and tissue engineering. We have developed chitosan scaffolds, with various pore size, by differing freezing temperature and duration of ultraviolet (UV) irradiation, for reconstructing skin equivalent. Chitosan scaffold was coated with type I collagen, fibronectin and basic fibroblast growth factor (bFGF) in various combinations and concentrations, to evaluate the effect of extracellular matrix (ECM) and bFGF on cell adhesion, growth and differentiation of dermal fibroblasts. Human dermal fibroblasts, isolated from newborn foreskin and passaged between 3 and 5, were seeded on the top of scaffolds and cultivated for 2 weeks. We examined the morphology and the secretion of ECM of fibroblasts using scanning electron microsopy (SEM) and histochemistry. A stellate morphology of fibroblasts were seen in all groups. The scaffold coated with either type I collagen and bFGF or type I collagen and fibronectin, however, showed the best condtion of dermal fibroblasts, in that the highest cell number and ECM secretion were seen. On the contrary, scaffolds coated with all three factors, type I collagen, bFGF and fibronectin, showed lower number of cells and ECM secretion than scaffolds with two factors. There was a tendency of dose-dependence in all three factors for fibroblast growth and ECM secretion. In conclusion, we may suggest that chitosan scaffold coated with either type I collagen/bFGF or type I collagen/fibronectin could provide more favorable environment for the growth and differentiation of dermal fibroblasts.

• Journal of Radiation Protection and Research
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• v.27 no.1
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• pp.51-57
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• 2002

An electronic personal dosimeter(EPD) with hybrid type preamplifier adopting a semiconductor detector as a radiation detector has been developed, manufactured and test-evaluated. The radiation detection characteristics of this EPD has been performance-tested by using a reference photon radiation field. After several test-irradiations to a $^{137}Cs$ gamma radiation source the radiation detection sensitivity of this EPD appeared to be $3.8\;cps/Gy{\cdot}h^{-1}$. The linearity of radiation response was kept within 8% of the dose equivalent ranges of $10{\mu}Sv{\sim}4Sv$ and the angular dependence was under less than 4% in angles of ${\pm}60^{\circ}$. It was confirmed that the energy response range was in $60{\sim}1,250keV$ given in the ISO standard. This EPD satisfied the international criteria for the EPD in the mechanical and the environmental performance test for 9 test categories according to IEC 61526.

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.241-245
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• 2007

In this study, a two-dimensional fiber-optic radiation sensor has been developed using water-equivalent organic scintillators for photon beam therapy dosimetry. Two-dimensional photon beam distributions and percent depth doses(PDD) are measured according to the energies and field sizes of the photon beam. This sensor has many advantages such as high resolution, real-time measurement and ease of calibration over conventional radiation measurement devices.