• Journal of Pharmaceutical Investigation
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• v.35 no.2
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• pp.117-122
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• 2005

After establishing improved HPLC analytical method of cefaclor in human plasma samples, a bioavailability study of cefaclor capsules was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). The standard calibration curve using an HPLC with UV detector was constructed in a range of $0.0324{\sim}16\;{\mu}g/ml$. The 6% perchloric acid instead of 6% trichloroacetic acid was used to precipitate plasma protein. The HPLC chromatograms were precisely and accurately resolved when spiked with human plasma spiked with cefaclor and cephalexin (internal standard). Twenty healthy male Korean volunteers received two commercial cefaclor capsules, $Neocef^{\circledR}$ capsule (Jinyang Pharm. Co., Ltd) or $Ceclor^{\circledR}$ capsule (Lilly Korea. Co., Ltd.) at the 250 mg cefaclor in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of cefaclor were monitored for 8 hours after oral drug administration. $AUC_t$ the area under the plasma concentration-time curve from time zero to 8 hr (13 points), was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the cross-over design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Neocef^{\circledR}/Ceclor^{\circledR}$ were $0.9049{\leq}{\delta}{\leq}1.226$, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the bioequivalence of $Neocef^{\circledR}/Ceclor^{\circledR}$ with respect to the extent of absorption.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.250-250
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• 2017

Studies were conducted to select the optimum sowing date and planting density of sesame in the middle area of Korea. To select the optimum sowing date, sesame seeds sowed from 20 April to 7 July with 15-day intervals. To select the optimum planting density, sesame seeds investigated under four different planting distances ($30{\times}10,\;30{\times}15,\;30{\times}20$, and $30{\times}25cm$)respectively in the experimental field. As seeding date was delayed, days to emergence were shortened flowering and maturing date were delayed. Delayed sowing date resulted in decreased length, capsule setting stem length and number of capsules, and branchs per plant. Number of Capsules was high sowing date on 5 May in the range of 90~95ea/plant in sesame. Also yield of sesame seeds was most high on 5 May in the range of 142kg/10a by sowing date. Sowing date up to 5 May showed no effect on grain yield, but from 5 June to 5 July decreased 27%, 68% and 86%, respectively. For all planting distances, weight of 1,000 grain was not significantly different. However, number of branches and capsules tended to increase. Number of Capsules was high planting distance of $30{\times}20cm$ and $30{\times}25cm$ in the range of 146.7~165.7ea/plant in the Geonbaekkae. Areumkkae also showed the same tendency on planting distance of $30{\times}20cm$ and $30{\times}25cm$ in the range of 122.0~147.5ea/plant, respectively. Yield of Geonbaekkae and Areumkkae seeds was most high 116kg/10a, 117kg/10a, respectively on planting distance $30{\times}20cm$. Decreased in the planting distance of sesame has increased the incidence of disease and lodging. Based on the results, we suggest a planting distance of $30{\times}20cm$ maximal growth and yield of sesame in the middle area of Korea. Considering growth characteristics, sesame yield ability, the optimum sowing date was 5 May and optimum planting pattern was founded to be two rows planting in one ridge and planting densities was $30{\times}20cm$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.857-867
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• 2017

This study was performed to encapsulate low molecular weight marine collagen and ${\gamma}$-aminobutyric acid (GABA)-producing lactic acid bacteria to inhibit degradation and improve survival rate during exposure to adverse conditions of the gastro-intestinal tract. Calcium-alginate method was used for the manufacture of a double-layered coated capsule. The inner core material was composed of collagen and lactic acid bacteria, and the coating materials were alginate and chitosan. The sizes and shapes of the double-coated capsule were affected mainly by centrifuge speed and pH. Manufactured capsules were observed with a scanning electron microscope and by confocal laser scanning microscopy to confirm the micromorphological changes of capsules and bacterial cells. As a result, double-layered coated capsules were not degraded at pH 1.2, whereas degradation occurred at pH 7.4. In addition, GABA and collagen were maintained in stable state at pH 1.2. Therefore, double-layered coated capsules developed in this study would not be degraded in the stomach and could be stably delivered to the small intestine to benefit intestinal and dermatic health.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.161-165
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• 2000

Gastric acid resistance of aerobic Lactobacilli and anaerobic Bifidohacteria in commercial 19 drink and 18 liquid yogurts in Korea was investigated after exposure to simulated gastric fluid (pH 1.5). The initial survival of Lactobacilli in commercial drink and liquid yogurts was $10^8~10^{10}$ cfulml and $10^6~10^{10}$cfdml, respectively. On the other hand, the initial survival of Bifidobacteria in commercial drink yogurts was ($10^6~10^{10}$cfulml. The survival of Lactobacilli and Bifidobacteria in some commercial drink and liquid yogurts drastically changed depending on the type of commercial products when exposed to simulated gastric fluid for 120 min (<$10^3~10^6$ cfulml). Their survival decreased as a function of time in the simulated gastric fluid. In the case of drink yogurt containing Bifidobacteria-loaded capsu1es;the survival of Bifidobactena in only Mi after excluding capsules was similar to other commercial drink yogurts after exposure to gastric fluid for 30-120 min (ca. TEX>$10^5$ cfulml). However, the survival of Bifidobacteria in capsules was greatly enhanced due to their stability in low pH condition (>$10^8$ cfulml). The drink yogut containing Bifidobacteria-loaded capsules showed about 10-737 times higher survival in the gastric fluid for 120 min when compared to other commercial drink yogurts. It was evident that the gastric acid resistance of Bifidobacteria could be increased when encapsulated.

• Korean journal of applied entomology
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• v.42 no.2
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• pp.145-152
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• 2003

Field application of the entomopathogenic nematode, Steinernema carpncapsae, is limited by its susceptibility to UV irradiation and desiccation especially at leaf spray control. This study was conducted to develop the control technique using alginate biocapsulation of the nematodes against the beet armyworm, Spodoprera exigua and the tobacco cutworm, Sp. litura that are normally infesting hosts above ground level. The alginate capsules including infective juveniles gave significant feeding toxicities to the larvae of the two lepidopteran species. The lethality followed a typical sigmoid dose-mortality pattern with increase of the nematode densities embedded in the capsules. Moisture content in the capsule was critical to the survival of the infective juveniles. More than 80% nematodes could survive above 10% moisture content remained in the capsule. Remaining moisture content within the capsule was dependent on relative humidity, ambient temperature, and capsule size, but not on citric acid reaction time during capsule formation. More than 80% of infective juveniles in the alginate capsules could survive in distilled water at 15$^{\circ}C$ for 60 days. When these nematode capsules containing welsh onion extract as another phagostimulant were applied on the 3rd instar larvae of Sp. exigua infesting peanut plants, they resulted in about 90% control efficacy. These results indicate that the alginate capsulation can be used for leaf-spray agent of the entomopathogenic nematodes as well as for improved storage purpose.

• Journal of Pharmaceutical Investigation
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• v.29 no.3
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• pp.227-234
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• 1999

Solid dispersions were prepared to increase the dissolution rate of biphenyl dimethyl dicarboxylate (DDB) using water-soluble carriers such as povidone, copolyvidone, $2-hydroxypropyl-{\beta}-cyclodextrin (HPCD)$, sodium salicylate or sodium benzoate by solvent evaporation method. Solid dispersions were characterized by infrared spectrometry, differential scanning calorimetry (DSC) and powder X-ray diffractometry, dissolution and permeation studies. DDB tablets (7.5 mg) were prepared by compressing the powder mixtures composed of solid dispersions, lactose, com starch, crospovidone and magnesium stearate using a single-punch press. DDB capsules (7.5 mg) were also prepared by filling the mixtures in empty hard gelatin capsules (size No.1). From the DSC and powder x-ray diffractometric studies, it was found that DDB was amorphous in the HPCD or copolyvidone solid dispersions. Dissolution rates after 10 min of DDB alone and solid dispersions (1 : 10) in sodium benzoate, sodium salicylate and copolyvidone were 11.8, 23.5, 22.8 and 82.5%, respectively. Dissolution rates of DDB after 30 min from 1 : 10 and 1 : 20 copolyvidone solid dispersions were 80.5 and 95.0%, respectively. For the DDB tablets prepared using solid dispersions (1 : 20), the initial dissolution rate was dependent on carrier material, and was ranked in order, $Kollidon\;30\;{\ll}$ copolyvidone < HPCD. For the HPCD solid dispersion tablets, dissolution rate reached 97.4% after 15 min, but thereafter slowly decreased to 80.7% after 2 hr due to the precipitation of DDB. However, in the case of copolyvidone solid dispersion tablets, dissolution increased linearly and reached 93.4% after 2 hr. Reducing the volume of test medium from 900 to 300 ml markedly decreased the dissolution rate of the tablets containing 1 : 20 HPCD solid dispersions and 1 : 10 copolyvidone solid dispersion. For 1 : 20 copolyvidone solid dispersion tablets, there was no significant change in dissolution rate up to 1 hr with different volumes of test medium. Preparation of the copolyvidone solid dispersion (1 : 20) in capsules markedly delayed the dissolution (31.2 % after 2hr) due to the limited diffusion within capsules. The permeation rate $(13.4\;g/cm^2\;after\;8\;hr)$ of DDB through rabbit duodenal mucosa from copolyvidone solid dispersion (1 : 10) was markedly enhanced, when compared with drug alone or physical mixtures. From overall findings, DDB formulations containing copolyvidone solid dispersions (1 : 20) could be used to remarkably improve the dissolution rate in dosage form of powders and tablets.

• Polymer(Korea)
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• v.28 no.5
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• pp.404-411
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• 2004

The microcapsules containing triphenyl phosphate (TPP), a flame retardant, were prepared by phase-inversion emulsification technique using the epoxy resin (Novolac type) with excellent physical properties and network structure. This microencapsulation process was adopted for the protection of TPP evaporation and wetting of polymer composite during the polymer blend processing. The TPP, epoxy resin and mixed surfactants were emulsified to oil in water (O/W) by the phase inversion technology and then conducted on the crosslinking of epoxy resin by in-situ polymerization. The capsule size and size distribution of TPP capsules was controlled by mixed surfactant ratio, concentration and TPP contents, The formation and thermal property of TPP capsules were measured by differential scanning calorimetry and thermogravimetric analysis. The morphology and size of TPP capsules were also investigated by scanning and transmission electron microscopies. As the surfactant concentration increased, the TPP capsules were more spherical and mono-dispersed at the same weight ratio of mixed surfactants (F127: SDBS).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2C
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• pp.109-117
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• 2010

Gas hydrate dissociation can generate large amounts of gas and water in gas hydrate bearing sediments, which may eventually escape from a soil skeleton and form voids within the sediments. The loss of fine particles between coarse particles or collapse of cementation due to water flow during heavy or continuous rainfall may form large voids within soil structure. In this study, the effect of void formation resulting from gas hydrate dissociation or loss of some particles within soil structure on the strength of soil is examined. Glass beads with uniform gradation were used to simulate a gas hydrate bearing or washable soil structure. Glass beads were mixed with 2% cement ratio and 7% water content and then compacted into a cylindrical sample with five equal layers. Empty capsules for medicine are used to mimic large voids, which are bigger than soil particle, and embedded into the middle of five equal layers. The number, direction, and length of capsules embedded into each layer vary. After two days curing, a series of unconfined compression tests is performed on the capsule-embedded cemented glass beads. Unconfined compressive strength of cemented glass beads with capsules depends on the volume, direction and length of capsules. The volume and cross section formed by voids are most important factors in strength. An unconfined compressive strength of a specimen with large voids decreases up to 35% of a specimen without void. The results of this study can be used to predict the strength degradation of gas hydrate bearing sediments in the long term after dissociation and loss of fine particles within soil structure.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.160-160
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• 2002

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.805-807
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• 2005