• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제1회 추계심포지움 and 제2회 생리분자과학연구센터워크숍
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• pp.21-24
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• 1993

Many attempts have been made to use hydrogel as del ivory systems for various drug and vioactive materials to prolong and control their pharmacological activities. Rectal administration of drugs by using hydrogel bases, such as poloxamer ABA block copolymer (Pluronic F-127) gels, polyacrylic acid (Carbomer 934, 940, or 941) aqueous gels, and polyvilyl alcohol gels, have been reported on the preparation and potential suppository use of new gels(Eudragit L, Eudragit S, and Eudispert) that are block copolymers of methacrylic acid and methyl methacrylate. If) These hydrogel and xerogel preparations, especially Eudispert hv gels, show excellent staying and bioadhesive effects in the lower part of the rectum in rats and rabbits compared with those of polyethylene glycol (PEG)2000 and Witepsol H-15(or S-55) suppositories. Visual and optical microscopic observation of rectal membrances indicated no irritation or abnormality after administration of Eudispert hv tydrogel and xerogel.

• Archives of Pharmacal Research
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• 제29권10호
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• pp.921-927
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• 2006

Prolonged release micro particles of clarithromycin (CL) were prepared using Eudragit RL 100 and RS 100 by spray-drying and casting-drying techniques. For the characterization of those microparticles, preparation yield, particle size distribution, X-ray diffraction, thermal behavior, active agent content and in vitro dissolution from the microparticles were performed. HPLC was used for the assay of clarithromycin and the assay method was validated. All the formulations obtained showed prolonged release when compared to pure clarithromycin. Microparticles prepared by spray-drying method had a slower release compared to those of casting drying method. Spray-drying method seems to be a more suitable method to prepare microparticles for prolongation in release.

• 약학회지
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• 제39권6호
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• pp.593-599
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• 1995

Erythromycin was formulated as enteric-coated pellets in order to reduce degradation in stomach and gastromtestmal irritation, and to maximize the absorption in intestine followmg its oral administration. Core pellets were prepared using fluid-bed granulator with two different methods (powder layering and solvent spraying) and enteric-coated with two different coating polymers (HPMCP and Eudragit E30D). Physical characteristics md dissolution rates of core pellets and enteric-coated pellets were evaluated to optimize the formulation. Powder layering method resulted in shorter initial dissolution time than solvent spraying method, but physicochmical properties of the product were worse than solvent spraying method with respect to hardness, ftiability and density. The dissolution rate of the drug was increased with the addition of surfactants, showing concentration-dependence. The scanning electron microscopic observation of pellets revealed significant differences on the surface appearances prepared with solvent spraying method. The core pellet made with powder layering method had crystals on the surface, which resulted in poor physical properties of the pellets. The dissolution profiles of erythromycin pellets coated with HPMCP or Eudragit L30D were close to that of commercially available erythromycin enteric-coated product.

• Journal of Pharmaceutical Investigation
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• 제28권1호
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• pp.51-57
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• 1998

Tetracycline lyogel ointment consisting of hydroxy ethyl cellulose(HEC) in glycerin and Eudragit RS 100 in triacetin were prepared and then release characteristic were investigated. The physical properties of lyogel ointment such as viscosity, particle size and microscopic structures were also evaluated. The microscopic structures showed that lyogel particles containing drug were dispersed in the triactin solution. The release rate of drug from lyogel ointment as a function of HEC was not changed. However the release rate was significantly decresed when the amount of Eudragit RS 100 and triacetin in lyogel ointment was increased. The viscosity and weight fraction in external phase of lyogel ointment influenced the release rate. The current studies suggest that the release rate of drug can be controlled by changing of lyogel ointment compositions.

• Journal of Pharmaceutical Investigation
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• 제29권3호
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• pp.185-191
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• 1999

The polymeric films containing drug and various excipients were fabricated using aqueous-based $Eudragit^{\circledR}$ RS 30D dispersions. The diffusional behaviors and mechanism of the fabricated polymeric film were investigated using Keshary-Chien diffusion cell. The melatonin was used as a model drug. The diffusion behaviors of drug through the fabricated polymeric films were highly dependent on drug concentration in donor part, polymer contents and drug concentration, and the types of plasticizers and solubilizers. The fabricated polymeric films containing excipients and solubilizers could be applied for the controlled release of poorly water-soluble drug and for the preparation of drug-containing latex films for topical or oral drug delivery.

• KSBB Journal
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• 제19권3호
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• pp.178-186
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• 2004

복합한방 재료인 옥용산에 대해 UV 흡수능, tyrosinase 저해활성 그리고 free radical 소거활성을 측정함으로서 미백활성을 검정하고 비교 시험군으로서 비타민C와 함께 Eudragit 이 코팅된 coconut oil을 이용한 SLN을 제조할 수 있었다. 실험 결과, 옥용산은 UV 영역에서 흡수능을 가지며 tyrosinase 저해 활성과 free radical 소거활성을 가진 것으로 확인되었다. 제조된 E-SLN을 TEM을 이용하여 관찰한 결과 크기 50∼300 nm인 구형의 양호한 입자를 형성하고 있음을 확인하였다. 또한 그 크기분포와 캡슐화 효율 분석을 통해 EUD의 농도가 2.0% (w/v), w/o 비율은 1 ： 9, emulsion과 pour solution의 비율은 1 : 10, 그리고 실온에서 제조한 E-SLN의 캡슐화 효율이 가장 높고 크기의 분포가 가장 양호한 것을 알 수 있었다. E-SLN을 이용하여 in vitro 방출시험을 실시한 결과 E-SLN은 pH와 온도 의존적으로 약물을 방출하는 경향을 나타냈다. 결과적으로 제조된 E-SLN은 pH와 온도 의존적으로 약물을 전달할 필요가 있는 계에 대한 약물전달 시스템으로 적합할 것으로 보인다. 폐쇄 첩포시험과 자외선 조사에 의한 인공색소침착과 시료도포에 의한 미백효능 판정에 의한 임상시험 결과 옥용산과 비타민C, 그리고 이를 포함하는 E-SLN은 대조군의 경우와 비교하여 미백효과를 가지는 것으로 확인되었으며 이는 기능성화장품에의 응용 가능성을 높여주었다.

• Archives of Pharmacal Research
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• 제18권3호
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• pp.183-188
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• 1995

Polymeric reinforcement and coatings of alginate beads were carried out to control the release rate of drug from alginate beads. A poorly water-soluble ibuprofen (IPF) was selected as a model drug. A commercially available $Eudragit^{\circledR}$ RS100 was also used as a polymer. Effects of polymeric contents, the presence of plasticizers and amount of drug loading on the release rate of drug were investigated. The release rate of drug from alginate beads in the simulated gastric fluid did not occur within 2 h but released immediately when dissolution media were switched to the simulated intestinal fluid. No significant difference of release rate from polymer-reinforced alginate bead without plasticizers was observed when compared to plain (simple) beads. However, the release rate of drug from polymer-reinforced alginate beads was further sustained and retarded when aluminium tristearate (AT) as a plasticizer was added to polymer. However, polyethylene glycol 400 (PEG400) did not change the release rate of drug from alginate beads although PEG400 was used to improve dispersion of polymer and sodium alginate, and plasticize $Eudragit^{\circledR}$ RS100 polymer. The presence of plasticizer was crucial to reinforce alginate gel matrices using a polymer. As the amount of drug loading increased, the release rate of drug increased as a result of decreasing effects of polymer contents in matrices. The significantly sustained release of drug from polymer-coated alginate beads occurred as the amount of polymer increased because the thickness of coated membrane increased so that cracks and pores of the outer surface of alginate beads could be reduced. The sustained and retarded action of polymer-reinforced and coated beads may result from the disturbance of swelling and erosion (disintegration) of alginate beads. From these findings, polymeric-reinforcement and coatings of alginate gel beads can provide an advanced delivery system by retarding the release rate of various drugs.

• Journal of Pharmaceutical Investigation
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• 제39권6호
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• pp.401-409
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• 2009

Ketrorolac tromethamine (KT), a nonsteroidal anti-inflammatory drug (NSAID) is required repeated administration due to its short blood half-life. To avoid dose-dependent side effects of KT, sustained-release pellets containing KT were prepared by coating with Eudragit$^{(R)}$ RS 100 and Eudragit$^{(R)}$ NE 30D. The in vitro and in vivo drug release behavior of KT from Eudragit$^{(R)}$ RS 100 and NE 30D coated pellet (SR-A), Eudragit$^{(R)}$ RS 100 coated pellet (SR-B) and conventional commercial immediate-release tablet (IR) was investigated. KT from SR-A and SR-B was slowly released over several hours, whereas IR showed rapid initial release in vitro. The pharmacokinetic study in vivo was performed by oral administration in beagle dogs. 5 mg IR was administered 3 times at intervals 5 hr. Five milligrams of IR was administered 3 times at intervals of 5 hr and 15 mg of SR-A and SR-B did once. After administering IR, KT concentration in blood showed high peak- trough fluctuation and stomach ulcer were discovered. On the other hand, SR-A and SR-B sustainedly released KT and reduced the occurrence of stomach ulcer. There sustained-release pellets will be effective system to minimize dosedependent of side effect and improve patient compliance.

• Archives of Pharmacal Research
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• 제26권7호
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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.

• KSBB Journal
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• 제26권3호
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• pp.217-222
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• 2011

Itraconazole is a triazole antifungal agent to inhibit most fungal pathogens. To improve the oral absorption and dissolution of poorly water-soluble itraconazole, microsponge system composed of $Eudragit^{(R)}$ E100 and polyvinyl alcohol(PVA) formulated by quasi-emulsion solvent diffusion method, and its physicochemical properties and pharmacokinetic parameters of itraconazole were studied. The microsponge of itraconazole were discrete free flowing micro sized particles with perforated orange peel like morphology as visualized by scanning electron microscope (SEM). Results showed that the drug loading efficiency, production yield, and particle size of itraconazole microsponge were affected by drug to polymer ratio, the volume of internal phase containing methylene chloride, stirring rate and the concentration of PVA used. Also, the results showed that the dissolution rate of itraconazole from the microsponges was affected by drug to polymer ratio. In other words, the release rate of itraconazole from microsponges was increased from at least 27.43% to 64.72% after 2 h. The kinetics of dissolution mechanism showed that the dissolution data followed Korsmeyer-Peppas model. Therefore, these results suggest that microsponge system can be useful for the oral delivery of itraconazole by manipulating the release profile.