• Title/Summary/Keyword: controlled release formulations

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Controlled Release of Oxyfluorfen from the Variously Complexed Formulations - II. Selection of Promising Formulations (수종(數種) 결합제형(結合劑型)으로부터 Oxyfluorfen의 방출제어(放出制御) 연구(硏究) - II. 유용(有用)한 방출제어형(放出制御型의) 선발(選拔))

  • Guh, J.O.;Im, W.H.;Lim, K.P.;Cho, C.S.;Chung, I.W.
    • Korean Journal of Weed Science
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    • v.10 no.3
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    • pp.207-213
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    • 1990
  • Thirty formulations of oxyfluorfen(2-chloro-2,2,2-trifluoro-p-toyl 3-ethoxy-4-nitrophenyl ether were manufactured by adsorption and substitation. Of them 16 formulations n-ere selected because they showed rekatuvely high activity and long durability in the bioassay with (Brassica campestris V.L.) Then, the formulations selected and 4 commercial formulations were tested using Monochoria in pots. As the result, the formulations of polyer 11, elvan 7/40, coal-slag 7/40, zeolite(A), and bentonite(A) were selected because they showed almost complete inhibition of Monochoria even up the 73 days after treatment.

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Controlled Release of Oxyfluorfen from the Variously Complexed Formulations V. Effect of Water Leakage on Injury and Efficacy of Selected Formulations (수종(數種)의 결합제형(結合劑型)으로부터 Oxyfluorfen의 방출제어연구(放出制御硏究) V. 감수심(減水深)에 따른 선발제형(選拔劑型) Oxyfluorfen의 약해(藥害).약효평가(藥效評價))

  • Guh, J.O.;Kwon, O.D.;Kuk, Y.I.;Chon, S.U.
    • Korean Journal of Weed Science
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    • v.11 no.3
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    • pp.167-173
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    • 1991
  • Various formulations of oxyfluorfen were tested to evaluate effect of weed control efficacy and rice injury as affected by different degrees of water leakages. Rice injury was increased with increased water leakages. The formulations of Elvan, Coal slag and Chitosan gave slight injury to rice under all conditions included in terms of visual ratings, plant height and fresh weight production. However, weed control of most formulations was decreased and increased with increased water leakages for annual weeds and perennial weeds, respectively, Annual weeds were controlled greater than 90~ by all treatments, but perennial weed control was relatively low. Scirpus juncoides was the most tolerant annual weed to Oxyfluorfen. Elvan formulation showed somewhat decreased control of barnyardgrass with increased water leakages. The promising formulations of Oxyfluorfen were Chitosan, Coal slag, Bentonite B and Elvan (if the first releasing rate increased), which injured rice slightly and controlled annual weeds excellently regardless of degrees of water leakages.

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Parenteral Formulations Based on Albumin Particulate Technology

  • Lee, Hong-Hwa;Lee, Min-Jung;Heo, Sun-Ju;Sah, Hong-Kee
    • Journal of Pharmaceutical Investigation
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    • v.40 no.spc
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    • pp.83-95
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    • 2010
  • Over the years, nanoparticle drug delivery systems have demonstrated versatile potentials in biological, medical and pharmaceutical applications. In the pharmaceutical industry nanotechnology research has mainly focused on providing controlled drug release, targeting their delivery to specific organs, and developing parenteral formulations for poorly water soluble drugs to improve their bioavailability. Achievement in polymer industry has generated numerous polymers applicable to designing nanoparticles. From viewpoints of product development, a nanocarrier material should meet requirements for biodegradability, biocompatibility, availability, and regulatory approval crieteria. Albumin is indeed a material that fulfills such requirements. Also, the commercialization of a first albumin-bound paclitaxel nanoparticle product (Abraxane$^{TM}$) has sparked renewed interests in the application of albumin in the development of nanoparticle formulations. This paper reviews the intrinsic properties of albumin, its suitability as a nanocarrier material, and albumin-based parenteral formulation approaches. Particularly discussed in detail are albumin-based particulate injectables such as Abraxane$^{TM}$. Information on key roles of albumin in the nab$^{TM}$ technology and representative manufacturing processes of albumin particulate products are provided. It is likely that albumin-based particulate technology would extend its applications in delivering drugs, polypeptides, proteins, vaccines, nucleic acids, and genes.

Controlled Release Dosage Form of Narcotic Antagonist(II) : Biocompatibility and Pharmacokinetics of Naloxone Implant (마약길항제의 방출 제어형 제제 (제2보): 나록손 이식제제의 생체적합성 및 약물속도론적 평가)

  • Moon, Mi-Ran;Park, Joo-Ae;Lee, Seung-Jin;Kim, Hyung-Kuk;Kim, Kil-Soo
    • Journal of Pharmaceutical Investigation
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    • v.25 no.2
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    • pp.117-123
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    • 1995
  • For the effective administration of narcotic antagonist, the application of sustained release implantable systems with biodegradable polyphosphazene was examined. Using poly[(diethyl glutamate)-co-(ethyl glycinate) phosphazene], the implantable devices containing naloxone hydrochloride were prepared and in vivo implantation studies were carried out subcutaneously in rat and rabbit with this preparation for the biocompatibility and pharmacokinetics. The histological finding in rats at initial time period was the inflammation that occurred focally around the implants, but they were showed subsequent mild and limited chronic inflammations and the irreversible changes such as necrosis and degeneration of the muscle or connective tissues were not observed. Therefore the placebo and naloxone implants are considered to be biocompatible formulations histologically. In pharmacokinetic studies, the release of naloxone from the naloxone implants into blood plasma was maintained in 192 hours, but the initial burst effect was observed. If this problem was solved, the application for the narcotic antagonist sustained release systems can be expected.

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Enhanced Antigen Delivery Systems Using Biodegradable PLGA Microspheres for Single Step Immunization

  • Cho, Seong-Wan;Kim, Young-Kwon
    • Biomedical Science Letters
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    • v.12 no.4
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    • pp.443-450
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    • 2006
  • To demonstrate their possibilities as an enhanced vaccine delivery system, protein-loaded Poly lactide glycolide copolymer (PLGA) microspheres were prepared with different physical characteristics. Ethyl acetate (EA) solvent extraction process was employed to prepare microspheres and the effects of process parameters on drug release properties were evaluated. The biodeuadability of microspheres was also evaluated by the pH change and GPC (Gel permeation chromatography). Primary IgG antibody responses in BALB/c mice were compared with protein saline solutions as negative controls and adsorbed alum suspensions as positive controls after single subcutaneous injection for in vivo studies. The microspheres showed a erosion with a highly porous structure and did not keep their spherical shape at 45 days and this result could be confirmed by GPC. In vitro release of proteinous drug showed initial burst effect in all batches of microspheres, followed by gradual release over the next 4 weeks. PLGA microspheres were degraded until 45 days and the secondary structure of OVA was not affected by the preparation method. Enzyme-linked immunosorbent assays demonstrated that the single subcutaneous administrations of OVA-loaded PLGA microspheres induced enhanced serum IgG antibody response in comparison to negative and positive controls. These results demonstrated that microspheres providing the controlled release of antigens might be useful in advanced vaccine formulations for the parenteral carrier system.

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A New Formulation of Controlled Release Amitriptyline Pellets and Its In Vivo/In Vitro Assessments

  • Park, Eun-Seok;Lee, Dong-Soo;Kwon, Seok-Young;Chi, Sang-Cheol
    • Archives of Pharmacal Research
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    • v.26 no.7
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    • pp.569-574
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    • 2003
  • Controlled-release amitriptyline pellets (ATP) were formulated and its oral bioavailability was assessed in human volunteers after oral administration under fasting conditions. Core pellets were prepared using a CF granulator by two different methods (powder layering and solvent spraying) and coated with Eudragit RS or RL 100. Physical characteristics and dissolution rates of core pellets and coated pellets were evaluated to optimize the formulation. Powder layering method resulted in a better surface morphology than solvent spraying method. However, physical properties of the products were poorer when prepared by powder layering method with respect to hardness, friability and density. The dissolution profile of amitriptyline coated with Eudragit RS 100 was comparable to that of commercially available amitriptyline enteric-coated pellets ($Saroten^{\circledR}$ retard). After the oral administration of both products at the dose of 50 mg, the mean maximum concentrations ($C_{max}$) were 36.4 and 29.7 ng/mL, and the mean areas under the concentration-time curve ($AUC_{0-96}$) were 1180.2 and 1010.7 ng.h/mL for ATP and Saroten retard, respectively. The time to reach the maximum concentrations ($T_{max}$) was 6 h for both formulations. Statistical evaluation suggested that ATP was bioequivalent to Saroten retard.

Insecticidal effects of Chitosan-formulated etofenprox and α-cypermethrin against Myzus persicae and Aphis gossypii (Homoptera: Aphididae) (키토산 캐리어 나노제형의 α-cypermethrin과 etofenprox의 목화진딧물과 복숭아혹진딧물에 대한 살충효과)

  • Seo, Mi-Ja;Kang, Min-Ah;Kwon, Hye-Ri;Yoon, Kyu-Sik;Kang, Eun-Jin;Yu, Yong-Man;Youn, Young-Nam;Youn, Young-Nam
    • Korean journal of applied entomology
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    • v.49 no.4
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    • pp.333-342
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    • 2010
  • The possibility of commercializing the controlled release of chitosan carrier nano formulation was examined with mortalities and population increase rates of Aphis gossypii and Myzus persicae after treatment of 2 ${\alpha}$-cypermethrin nano type formulations of different chitosan carrier molecular weight (M.W. 3,000 and 30,000) and 2 etofenprox nano types of chitosan content (70% and 80%). After 14 days of treatment, ${\alpha}$-cypermethrin nano formulation showed over 40% mortality against A. gossypii. Therefore, it was confirmed that the insecticide release was controlled through chitosan carrier. Results of the investigation of insecticidal activity of ${\alpha}$-cypermethrin nano formulation showed there were no differences between nano types at 4 days after treatment. However, after 14 days, the population increase rate treated with chitosan M.W. 30,000 formulation was -0.037, much lower than that of M.W. 3,000 formulation with 0.231. The result exhibits that chitosan M.W. 30,000 formulation would be a suitable controlled release formulation. On the other hand, etofenprox formulations didn't show any significant insecticidal effect or persistency difference against both aphid species.

Analysis of the influence degree of each factor on the linkage affecting the lever actuating force in an implant transport device for the treatment of eye diseases (안과질환 처치를 위한 임플란트 수송장치에서 레버 작동력에 영향을 주는 연동장치에 대한 인자별 영향도 분석 )

  • Jeong-Won Lee;Joong-Seob Guk
    • Design & Manufacturing
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    • v.18 no.3
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    • pp.1-8
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    • 2024
  • Macular degeneration is a disease that damages the macula, the center of the retina, and is one of the three major eye diseases along with glaucoma and diabetic retinopathy. The optic nerve and most of the photoreceptor cells are located here, and since this is where images of objects are formed, it is the most important area for vision. The main symptom of macular degeneration is the inability to clearly distinguish the shape of objects or the inability to distinguish colors and light and dark. It is also a serious eye disease that causes black spots in the center of the field of vision. However, it is difficult to distinguish it from the form of vision loss due to presbyopia, so early diagnosis is often missed. The most common treatment for macular degeneration is antibody injection therapy. This treatment requires regular injections once every 1-2 months. When receiving antibody injection therapy, the fear of having to inject directly into the eye and the cost of long-term repeated procedures are a great burden to patients. To overcome these problems, special sustained-release formulations using drug delivery systems are being developed. Since the release speed and release time of the drug can be controlled, the number of times the drug is administered can be drastically reduced. However, the implant (Ø 0.46×6.0mm), which is a sustained-release agent, is manufactured by mixing biodegradable resin (PLGA) and therapeutic agent in a ratio of 4:6, so it is very brittle and there is a high risk of implant damage during handling. In order to safely insert the implant into the eye, a transport device that can be driven with controlled force is required. Therefore, in this study, the lever operating force was measured and analyzed to determine the influence of factors according to the cross-sectional thickness and shape of the linkage produced through injection molding as well as the post-process.

A Brief Replication Study Comparing Stimulants and Non-Stimulants for Attention-Deficit/Hyperactivity Disorder Treatment with a Focus on the Compliance, Efficacy, and Satisfaction

  • Roh, Hyosung;Kim, Bongseog
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.32 no.1
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    • pp.10-16
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    • 2021
  • Objectives: The aim of this study was to compare the compliance, efficacy, and satisfaction associated with methylphenidate and atomoxetine for treating attention-deficit/hyperactivity disorder (ADHD). Methods: The subjects were 44 patients who met the Diagnostic and Statistical Manual of Mental Disorder-5 diagnostic criteria for ADHD and were treated with methylphenidate or atomoxetine. The methylphenidate formulations included immediate release (IR), extended release (ER), and osmotic-controlled release oral delivery system (OROS). Patients and parents reported the average number of days per week the medication was taken. Efficacy was assessed using the ADHD Rating Scale. Satisfaction with medication scale (SAMS)-parent report form and SAMS-self-report form were used to evaluate parents' and patients' satisfaction, respectively. Results: Patients and parents were more satisfied with methylphenidate than with atomoxetine. There were no significant differences in the compliance with and efficacy of methylphenidate and atomoxetine. Compliance with methylphenidate IR and ER was markedly lower than that with OROS methylphenidate or atomoxetine. Conclusion: Methylphenidate OROS formulation can be considered a suitable option given its high rates of compliance, satisfaction, and efficacy.

Chemical and toxicological properties of controlled release granular formulations of acetamiprid using wax matrix (왁스매트릭스를 이용한 방출조절헝 acetamiprid 입제의 화학적, 독성학적 특성)

  • Lee, Weon-Kee;Yang, Kyung-Hyung;Lee, Chang-Hyuk;Lee, Seung-Il;Hwang, In-Cheon
    • The Korean Journal of Pesticide Science
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    • v.9 no.3
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    • pp.243-249
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    • 2005
  • The chemical and toxicological studies were conducted with acetamiprid 2% granules including different controlling agents for development of controlled-release acetamiprid 2% granule. The fundamental formulation recipe of acetamiprid 2% granule was prepared by the insoluble matrix using polyethylene wax. Starch, cellulose and mineral (calcium carbonate) were used as controlling agents. As a result of studies, release rate of active ingredient from granules into water static condition at $25^{\circ}C$ was increased by addition of starch and cellulose, but was decreased by addition of calcium carbonate. We could select calcium carbonate as controlling agent and make three granules which there were difference in release profiles of active ingredient according to contents of polyethylene wax. 24 hours-release rates of acetamiprid from three granules into water static condition at $25^{\circ}C$ were respectively 75, 50 and 25% when contents of wax were 2, 10 and 20%. The granule which 24 hours-release rate was 25% showed lower acute toxicity against mice and rats.