• Analytical Science and Technology
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• v.20 no.2
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• pp.176-182
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• 2007

The present study relates to a matrix-typed, sustained-releasing agent comprising agrochemical effective ingredients being capable of recognizing a content of moisture, and a preparation method thereof. The curdlan solution added to acid was formed matrix which has unique network structure. The matrix treated by heat lost water solubility. The network structure of matrix was opened in the aquatic condition but closed again in dry condition. Therefore, in the sustained-releasing formulation system, an agrochemical effective ingredient was released from the formulation only in the aquatic condition. Use of the composition according to the product can control a manifesting time of effects of agrochemicals and can provide agrochemicals with reduced harmful damages.

• Korean Journal of Veterinary Service
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• v.33 no.2
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• pp.173-176
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• 2010

Here, we report the suitability of using a resin-type chitosan formulae as a sustained-releasing form adjuvant in comparison with commercially well-known Freund's adjuvants. To induce the immunological responses, N-terminal region of Pasteurella multocida toxin was used as an antigen, which was found to be protective immunogen against P. multocida infection. Mice immunized with chitosan resin formulae showed statistically significant antibody induction (P<0.001) as much as that of Freund’s adjuvants. As a result, the resin-type sustained-releasing form chitosan formulae is thought to be a good candidate for a new type adjuvant.

• Korean Journal of Environmental Agriculture
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• v.11 no.2
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• pp.155-162
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• 1992

In order to extend the releasing period of granular formulation to approximately 20 days, the KC-6620-adsorbed granules were formulated with carriers and polyethylene glycol as adjuvant. The releasing rates of active ingredient from the formulations were evaluated in aqueous medium. The baked bentonite was found most effective carrier to sustain the release of KC-6620. Due to, however, low releasing rate of active ingredient after 20 days, bentonite formulation appeared to be of no practical for the short-term sustained release of KC-6620. The increased pore volume of bentonite granular formulation by adding pyrophyllite increased remarkably the released amount of KC-6620 from bentonite-pyrophyllite(4 : 6) granule up to 85% of total active ingredient incorporated. Addition of polyethylene glycol to the bentonite-pyrophyllite granule further increased the releasing rate of KC-6620. With KC-6620 content in the bentonite-pyrophyllite(4 : 6) granule, the releasing rate of active ingredient was markedly reduced.

• Journal of Veterinary Clinics
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• v.9 no.1
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• pp.333-366
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• 1992

Safety of recombinant porcine somatotropin administration on pig was studied using 32 Landrace x Yorkshire crossbred pigs. The starting body weight ranged from 55.5kg to 65.3kg. Eight pigs were allotted to each low dose group of sustained releasing rPST(SL), high dose group of sustained releasing rPST(SH), daily injection group of rPST(DI), and control group(C). Pigs in SL group and SH group were injected subcutaneously twice in 3 week-interval with 1000$\mu\textrm{g}$ and 2000$\mu\textrm{g}$ of sustained releasing rPST per kg body weight, respectively. Pigs in DI group were injected intramuscularly with 100$\mu\textrm{g}$ of rPST everyday for 6 weeks. Blood was collected from anterior vena cava just before the first treatment, and at four weeks and six weeks of experiment. Hematological parameters and blood chemical parameters indicating liver function, kidney function, electrolyte metabolism, mineral metabolism and lipid metabolism were determined. Necropsy and urinalysis were performed after final blood collection. The results were summarized as follows, and it is concluded that rPST administration does not affect pig health negatively. 1. rPST administration did not affect kidney function as manisfested by BUN, creatinine and urinalysis. 2. rPST administration did not affect liver function as manisfested by total protein, albumin, serum AST activity serum ALT activity serum ALP activity, serum LDH activity, serum GGT activity and serum SDH activity. 3. rPST administration did not affect skeletal muscle, cardiac muscle and brain as manifasted by serum AST activity and serum LDH activity. 4. rPST administration increased blood glucose level within normal range. 5. rPST administration did not affect lipid metabolism as manisfested by triglyceride, cholesterol, and phospholipid concentrati on. 6. rPst administration dia not affect mineral metabolism as manisfested by calcium, phosphorus, magnesium and iron concentration. 7. rPST administration did not affect electrolyte metabolism as manisfested by Na, K, chloride concentration. 8. rPST administration did not affect erythrocyte count, leukocyte count, thrombocyte count, and plasma fibrinogen level.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.171-176
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• 2013

In previous study, the novel nanosized curdlan-silica complex for a sustain-releasing effect was developed by using gamma-irradiation. It can be applicable to use in various sustainr-eleasing formulation in agriculture industry. This study was conducted to investigate its storage stability and environmental toxicity in an accelerated condition. The complex samples were treated with high temperature condition ($65^{\circ}C$) during 3 weeks, and then sustain-releasing property of complex was verified thereby using Ion Chromatography on a weekly basis. The morphology of the complex was characterized using scanning electron microscopy (SEM). Results of Ion Chromatography analysis showed that sample treated for 3 weeks was similar to sustain-releasing pattern of non-treatment sample. We verify concluded that the complex is able to keep its sustain-releasing property and sustained-releasing in 3 years. Also the formulation has no environmental toxicity.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.62.2-63
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• 2002

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.361-366
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• 2006

Sustained-releasing praziquantel (SRP) tablet was designed for single dose treatment regimen of clonorchiasis. A previous pre-clinical study confirmed its sustained-releasing characteristics and a better cure rate than conventional praziquantel (PZQ). In this clinical study, the pharmacokinetics of this SRP tablet were investigated in human volunteers (phase 1; 12 volunteers), and its curative efficacy was examined in clonorchiasis patients (phase 2; 20 volunteers). In the phase 1 clinical study, blood concentrations of both tablets showed wide individual variation. The $AUC_{last}$ of SRP was $497.9{\pm}519.0ng{\cdot}hr/ml\;(mean{\pm}SD)$ and PZQ of $628.6{\pm}695.5\;ng{\cdot}hr/ml$, and the $AUC_{inf}$ of SRP was $776.0{\pm}538.5\;ng{\cdot}hr/ml$ and of PZQ $658.6{\pm}709.9\;ng{\cdot}hr/ml$. $C_{max}$ values of SRP and PZQ were $90.7{\pm}82.2ng/ml\;and\;214.9{\pm}251.9\;ng/ml$, and $T_{max}$ values were $3.42{\pm}1.43\;hr\;and\;1.96{\pm}1.23\;hr$, respectively. SRP tablets showed similar AUC values, but lower $C_{max}$ and longer $T_{max}$ values than PZQ. In the phase 2 study, SRP at 30 mg/kg (single dose) achieved a 60% cure rate and a 95.5% egg reduction rate. The cure rate of a single dose SRP was unsatisfactory compared with that of the conventional PZQ dose, but much better than that achieved by a single dose PZQ.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.113-120
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• 2004

1% iodophor loaded microspheres of PLGA (Poly[DL-Lactide-co-Glycolide]) were prepared by solvent evaporation method and were applied to the cows on dry period for evaluating it's preventive effects on intramammary infections. The morphology of the microspheres were evaluated using scanning electron microscopy and their releasing patterns were investigated. On investigating idophor releasing patterns of the microsphere, burst releasing pattern was detected until 2 days after in vitro incubation and sustained releasing was observed until 4 weeks. In field trial of teat dipping solution containing idophor loaded microspheres in dry cows showed significant preventive effects of intramammary infection caused by S. aureus, S. agalactiae, coagulase negative Staphylococci and coliform bacteria (p<0.05).

• Journal of Pharmaceutical Investigation
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• v.26 no.2
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• pp.119-124
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• 1996

To develop oral controlled release dosage forms, ionic interactions between polymers and drugs were evaluated. Hydroxypropylmethyl cellulose and carboxymethylene were used as model nonionic and ionic polymers, respectively. 5-fluorouracil, propranolol-HCl and sodium salicylate were selected as model nonionic, cationic and anionic, respectively. Polymer-drug mixtures were compressed into tablets and drug release kinetics from these tablets were determined. Drug release from the tablets made of the nonionic polymer was not affected by the charge of drugs, rather, was regulated by the solubility of drugs in different pH releasing media. However, drug release kinetics were significantly affected when drug-polymer ionic interactions exist. Enhanced drug release was observed from anionic drug-anionic polymer tablets due to ionic repulsion, whereas drug release was retarded in cationic drug-anionic polymer tablets owing to ionic attractive force. Therefore, the results suggested that the polymer-drug interactions are important factors in designing controlled release dosage forms.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.76-81
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• 1992

The technicals of KC-7079, isoprothiolane, perfluidone and tricyclazole were granulated with a mixture of inorganic carrier and oil-soluble binder, that is, stearly alcohol or ethyl cellulose. The concentration of the released active ingredient from the granules was analyzed at several days intervals after immersion of these granules in water at $25^{\circ}C$. At the content of stearyl alcohol less than $80g\;kg^{-1}$, the granule kneaded with stearyl alcohol mixture and water disintegrated in water. But the granule kneaded with methanol disintegrated in water at the content of stearyl alcohol less than $30g\;kg^{-1}$. The less the KC-7079-stearyl alcohol granule disintegrated, the slower the release rate of KC-7079 was. No matter how was increased the stearyl alcohol content, the release rate of KC-7079 granule which did not disintegrate was not significantly changed. The sustained releasing effect of the granules was little in the other three pesticides of which the water solubility was higher than of KC-7079(21 ppm). The granule made of ethyl cellulose did not disintegrate even at $5g\;kg^{-1}$ of ethyl cellulose. With the increase of ethyl cellulose content and the decrease of active ingredient in the granules, the sustaining effect of the granules on releasing acitive ingredient was increased. The lower the water solubility of pesticide was, the release rate tended to be sustained except perfluidone.