• Journal of the Korean Ceramic Society
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• v.54 no.3
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• pp.228-234
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• 2017

This work was achieved on the preparation of antimicrobial ceramic hybrid polyethylene films with natural chamomile extracts. The antimicrobial activity and various physicochemical properties of the prepared films were evaluated. Various natural products demonstrated antimicrobial activity. Among them, chamomile extracts showed strong activity and no cytotoxicity rather than that of the natural extracts. Porous ceramic materials were synthesized and demonstrated loading and controlled release of natural antimicrobial extracts. Furthermore, chamomile loaded ceramic hybrid films showed antimicrobial activity that was maintained for over 15 days.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.29-33
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• 1996

Mono-, or di-substituted chlorodicyanovinyl benzene compound was reacted with an excess amount of ethylenediamine to give corresponding imidazoline product with high reaction yield. This reaction occurs by stable imidazoline ring-forming process through nucleophilic attack of terminal amine on the enaminonitrile adduct, the reaction intermediate, toward electropositive enamine carbon, which is accompanied by the release of neutral malononitrile moiety. The similar reaction with 1,2-phenylenediamine produced stable enaminonitrile-amine adduct at lower temperature which could be cyclized intramolecularly to thermally stable benzimidazole at elevated temperature in solution or in solid state. From the difunctional compound of both reactants, poly(enaminonitrile-amine) could be prepared as a new soluble precursor polymer for well-known polybenzimidazole (PBI). The thermal cyclization reaction accompanying the release of malononitrile molecules was studied using thermalanalysis and infrared spectroscopy.

• Journal of Pharmaceutical Investigation
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• v.40 no.5
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• pp.313-319
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• 2010

The objectives of this study were to evaluate the effect of formulation ingredients on the drug release and to optimize the novel sustained release matrix tablet formulations of bupropion hydrochloride. A three factor, three-level Box-Behnken design was used for the optimization procedure, with the amounts of PEO ($X_1$), citric acid ($X_2$) and Compritol 888 ATO ($X_3$) as the independent variables. The selected dependent variables were the cumulative percentage values of bupropion hydrochloride that had dissolved after 1, 4 and 8 hr. Various dissolution profiles of the drug from sustained release matrix tablets were obtained. Optimization was performed for $X_1$, $X_2$ and $X_3$ using the following target ranges; $30%{\leq}Y_1{\leq}45%$; $70{\leq}Y_2{\leq}85%$; $85%{\leq}Y_3{\leq}100%$. The optimized formulation for bupropion hydrochloride was achieved with 12.5% PEO ($X_1$), 2.5% citric acid ($X_2$) and 10% Compritol 888 ATO ($X_3$). The sustained release matrix tablets with the optimized formulation provided a release profile that was close to predicted values. In addition, the dissolution profiles of the sustained release matrix tablet with the optimized formulation were similar to those of the commercial product Wellbutrin$^{(R)}$ SR tablets ($f_2$=79.83).

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.228-232
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• 2007

Slow-release fertilizers (SRF) have been used to reduce nutrient loss through increasing fertilizer efficiency and to save labor. Several SRFs were developed for rice plant in Korea, but there is few for horticultural crop plants. Two slow-release complex fertilizers, 100T and 150T, which made for controlling nitrogen release time up to 100 and 150 days, respectively, were selected for the incubation test cto evaluate nitrogen (N) release rate in soil. The N of urea selected as the control was completely released within a week after application. Sixty three and 53% of total N were released from 110T and 150T of slow release fertilizers within 8th weeks after application, respectively. For pepper cultivation CF110 and CF150, new slow-release complex fertilizer, were made of mixing 40% of conventional fertilizer and 60% of 110T and 150T, respectively, based on the amount of recommended fertilizer for pepper cultivation $(N-P_2O_5-K_2O=190-112-149\;kg\;ha^{-1})$, and were totally applied before pepper transplanting in the field as the basal fertilizer. Inorganic N $(NH_4^+-N+NO_3^--N)$ concentration in soil was higher in the CF110 treatment than in the control (NPK) at all period of pepper cultivation. In the CF150 treatment concentration of inorganic N in soil was low compared to control up to 8th weeks after transplanting. However, there was no difference in plant height and nutrient content of pepper leave between CF110 treatment and the control. In comparison, plant height was significantly lower in CF150 than the control and CF110 treatments. Around 4% of fresh pepper yield was increased in CF110 compared to the control, but it was decreased to about 2% by CF150 treatment. Conclusively, CF110 form could be recommended as a slow release fertilizer for pepper cultivation.

• Journal of Pharmaceutical Investigation
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• v.32 no.3
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• pp.185-190
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• 2002

To improve the solubility of poorly water-soluble drug and to develop a sustained release tablets, the need for the technique, the formation of solid dispersion with polymeric materials that can potentially enhance the dissolution rate and extent of drug absorption was considered in this study. The 1:1, 1:4, and 1:5 solid dispersions were prepared by spray drying method using PVP K30, ethanol and methylene chloride. The dissolution test was carried out at in phosphate buffer solution at $37^{\circ}C$ in 100 rpm. Solid dispersed drugs were examined using differential scanning calorimetry and scanning electron microscopy, wherein it was found that felodipine is amorphous in the PVP K30 solid dispersion. Felodifine SR tablets were prepared by direct compressing the powder mixture composed of solid dispersed felodipine, lactose, Eudragit and magnesium stearate using a single punch press. In order to develop a sustained-release preparation containing solid dispersed felodipine, a comparative dissolution study was done using commercially existing product as control. The dissolution rate of intact felodipine, solid dispersed felodipine and its physical mixture, respectively, were compared by the dissolution rates for 30 minutes. The dissolution rates of felodipine for 30 minutes from 1:1, 1:4, 1:5 PVP K30 solid dispersion were 70%, 78% and 90%. However, dissolution rate offelodipine from the physical mixture was 5% of drug for 30 minutes. Our developed product Felodipine SR Tablet showed dissolution of 17%, 50% and 89% for 1, 4, and 7 hours. This designed oral delivery system is easy to manufacture, and drug releases behavior is highly reproducible and offers advantages over the existing commercial product. The dissolution rate of felodipine was significantly enhanced, following the formation of solid dispersion. The solid dispersion technique with water-soluble polymer could be used to develop a solid dispersed felodipine SR tablet.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1725-1733
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• 2016

Recent findings have shown that microbial nitrogen flow and digestible energy of diets are increased when urea is combined with a slow-release urea (SRU) in diets with a starch to acid detergent fibre ratio (S:F) 4:1. This affect is attributable to enhanced synchrony between ruminal N availability for microbial growth and carbohydrate degradation. To verify the magnitude of this effects on lamb performance, an experiment was conducted to evaluate the effects of combining urea and a SRU in diets containing S:F ratios of 3:1, 4:1, or 5:1 on performance, dietary energetics and carcass characteristics of finishing lambs. For that, 40 Pelibuey${\times}$Katahdin lambs ($36.65{\pm}3kg$) were assigned to one of five weight groupings in 20 pens (5 repetition/treatments). The S:F ratio in the diet was manipulated by partially replacing the corn grain and dried distiller's grain with solubles by forage (wheat straw) and soybean meal to reach S:F ratios of 3:1, 4:1 or 5:1. An additional treatment of 4:1 S:F ratio with 0.8% urea as the sole source of non-protein nitrogen was used as a reference for comparing the effect of urea combination vs. conventional urea at the same S:F ratio. There were no treatment effects on dry matter intake (DMI). Compared the urea combination vs urea at the same S:F ratio, urea combination increased (p<0.01) average daily gain (ADG, 18.3%), gain for feed (G:F, 9.5%), and apparent energy retention per unit DMI (8.2%). Irrespective of the S:F ratio, the urea combination improved the observed-to-expected dietary ratio and apparent retention per unit DMI was maximal (quadratic effect, $p{\leq}0.03$) at an S:F ratio of 4:1, while the conventional urea treatment did not modify the observed-to-expected net energy ratio nor the apparent retention per unit DMI at 4:1 S:F ratio. Urea combination group tended (3.8%, p = 0.08) to have heavier carcasses with no effects on the rest of carcass characteristics. As S:F ratio increased, ADG, G:F, dietary net energy, carcass weight, dressing percentage and longissimus thoracis (LM) area increased linearly ($p{\leq}0.02$). Combining urea and a slow-release urea product results in positive effects on growth performance and dietary energetics, but the best responses are apparently observed when there is a certain proportion (S:F ratio = 4:1) of starch to acid detergent fibre in the diet.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2599-2605
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• 2013

The study aimed to evaluate immune-stimulating effects of a well-known Thai folkloric remedy when used for adjuvant therapy with conventional chemotherapeutics for treatment of breast cancer. Immunostimulating influence of the remedy (215 mg/kg body weight per day) on NK cell activity and TNF-${\alpha}$ release from the monocytes/macrophages were investigated in a total of 15 healthy women and 13 female patients with breast cancer (Group 1). The effect of breast tumor surgery on NK cell activity was further investigated in 18 female patients with breast cancer (Group 2). NK cell cytotoxic activity was determined by chromium release cytotoxic assay using K562, an erythroleukemic cell line. TNF-${\alpha}$ release from monocytes/macrophages separated from blood samples was determined through a biological assay using actinomycin D-treated L929 mouse fibroblast cells in the presence and absence of LPS. Baseline NK cell activity of the monocytes/macrophages separated from Group 2 patients expressed as %cytotoxicity was significantly lower than in the healthy subjects at E:T ratios of 100:1 and 25:1. In healthy subjects, there was no change in NK cell cytotoxic activity (%cytotoxicity or LU) following 1 and 2 weeks of treatment with the remedy compared with the baseline at various E:T ratios but the binding activity (%binding) was significantly increased after 2 weeks of treatment. The addition of one or two conventional chemotherapeutic regimens did not significantly reduce the NK cytotoxic activity but did affect release of TNF-${\alpha}$ in both unstimulated and LPS-stimulated samples. Surgery produced a significant suppressive effect on NK cell activity. The use of the remedy as an adjunct therapy may improve therapeutic efficacy and safety profiles of conventional chemotherapeutic regimens through stimulation of the immune system in cancer patients.

• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.471-481
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• 2005

In Korea, generic drug and bioequivalence test are the hot issues since a new medical system of separation of dispensary from medical practice was started in 2000. The KFDA(Korea FDA) had revised several times ${\ulcorner}Guidance\;for\;bioequivalence\;test{\lrcorner}$. In vitro dissolution test has been extensively used as a quality control tool for solid oral dosage forms. In an effort to minimize unnecessary human testing, in vitro/in vivo correlations (IVIVC) between in vitro dissolution and in vivo bioavailability are increasingly becoming an integral part on extended release drug product development. The recently published US guidance, ${\ulcorner}Extended\;release\;oral\;dosage\;forms\;:\;development,\;evaluation,\;and\;application\;of\;in\;vitro/in\;vivo\;correlations{\lrcorner}$ will be helpful for us to make our own guideline.

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.179-186
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• 1993

In vitro dissolution test and pharmacokinetic study in human volunteers were conducted to evaluate the pharmacokinetic characteristics of 150 mg furbiprofen sustained-release capsule (FPSR-150). As a reference product, 50 mg flurbiprofen conventional-release capsule (FPCR-50) was used. Dissolution tests of two products were run using the paddle method in 450 : 540 (v/v %) mixture of simulated gastric and intestinal fluids (K.P. VI) by adjusting medium pH according to time. FPCR-50 was dissolved very rapidly, and it took about 1.5 hr for FPCR-50 to be dissolved over 90%, whereas 15 hr for FPSR-150. Also, in pharmacokinetic study, ten healthy male volunteers were administered one capsule of FPSR-150 or two capsules of FPCR-50 (FPCR-l00) with randomized two period cross-over study. Significant differences between FPCR-l00 and FPSR-150 were found in mean times to reach peak concentration, mean resident times and mean terminal phase halflives, while not in AUC/Dose (Student's t-test). In ANOVA for AUC/Dose to compare the bioavailabilities of two FP products, there was no significant difference. From the comparison of the simulated steady-state plasma concentration-time curves following multiple medications of FPCR-50 (3 capsules a day, dosing interval=8 hrs) and FPSR-150 (1 capsule a day) based on the above results obtained from single doses of two FP products, it was noted that the medication of FPSR-150 is more useful in clinical application rather than FPCR-50.

• The Journal of Korean Medicine
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• v.17 no.1 s.31
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• pp.9-20
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• 1996

Oxygen free radicals can generated during metabolic processes in normal cells and by exposure of cells to toxic substances. These radicals have been recogenized to playa critical role in several pathological conditions including carcinogenesis and aging, and they have been implicated in pathogenesis of various diseases such as seizure, Alzheimer's disease, Parkinson's disease, myocardial infarction, respiratory distress syndrome, and rheumatoid arthritis. This study was undertaken to determine if Juglandis semen herb-acupuncture solution (JSHAS) has a protective effect against cell injury caused by oxidants, t-butylhydroperoxide (t-BHP) and $H_{2}O_2$. Cell injury was estimated by measuring lactate dehydrogenase (LDH) release and lipid perexidation was estimated by measurimg malondialdehyde, a product of lipid peroxidation. JSHAS significantly prevented LDH release induced by t-BHP or $H_{2}O_2$ in a dose-dependent manner at concentrations of 0.5-10%. Such protective effect was observed in control tissues untreated with oxidants. JSHAS, at 5% concentration, significantly reduced LDH release even when the concentrations of t-BHP and $H_{2}O_2$ increased to 5 and 200 mM, respectively. JSHAS, at 5% concentration, significantly reduced the lipid peroxidation by t-BHP and $H_{2}O_2$. These results indicate that JSHAS prevents cell injury and lipid peroxidation induced by oxidants in rabbit kidney cells. However, the underlying mechanisms remain to determined.