• Journal of Pharmaceutical Investigation
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• v.14 no.1
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• pp.1-10
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• 1984

Effects of water soluble carrier on the dissolution characteristics of indomethacin coprecipitates were investigated. Water soluble carriers used were polyvinylpyrrolidone, dextrose, mannitol and their mixtures of various ratios. The dissolution rates of indomethacin from coprecipitate with ratios of drug-to-carrier, kinds of carrier and ratios of carriers were as follows: 1. The dissolution rates increased proportionally to the ratios of carrier in the case of both single and combined carrier, and the dissolution rate of coprecipitate with the combined carrier was more rapid than that with single carrier. 2. The combined carrier of PVP-dextrose (1 : 2) in the case of the coprecipitate of drug-to carrier (1 : 1) and PVP-dextrose (4 : 1) in the case of the coprecipitate of drug-to carrier (1 : 3) yield the most rapid dissolution rate. 3. The dissolution rate of indomethacin was the most markedly enhanced in the case of the combined carrier of PVP and dextrose.

• YAKHAK HOEJI
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• v.20 no.1
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• pp.6-11
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• 1976

• Journal of Pharmaceutical Investigation
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• v.22 no.1
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• pp.1-10
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• 1992

The use of erythrocyte as drug carrier has been reviewed, Carrier erythrocytes have proven to offer many advantages for delivery of therapeutic agents, especially in the treatment of inherited enzyme deficiency and cancer. Carrier erythrocytes are biodegradable and nonimmunogenic. Encapsulated drugs may be protected from premature degradation, inactivation and excretion. Carrier erythrocytes may be used as a slow-release system. Targeting of encapsulated drugs directly to a site of action is another possibility. Methods for encapsulating drugs into erythrocytes, the fate of carrier erythrocytes in vivo, the strategies of targeting carrier erythrocytes to special organs and in vivo applications of erythrocytes have been discussed. The encapsulation of drugs in erythrocytes has shown attractive possibilites in future use.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.1
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• pp.1-13
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• 2015

Despite recent progresses in nanoparticle-based drug delivery systems, there are still many unsolved limitations. Most of all, a major obstacle in current nanoparticle-based drug carrier is the lack of sufficient drug delivery into target cells due to various biological barriers, such as: extracellular matrix, endolysosomal barrier, and drug-resistance associated proteins. To circumvent these limitations, several research groups have utilized photochemical internalization (PCI), an extension of photodynamic therapy (PDT), in design of innovative and efficient nano-carriers drug delivery. This review presents an overview of a recent research on utilization of PCI in various fields including: anti-cancer therapy, protein delivery, and tissue engineering.

• Macromolecular Research
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• v.12 no.1
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• pp.71-77
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• 2004

We have synthesized various types of poly(ethylene glycol) (PEG)-ibuprofen conjugates by nucleophilic substitution of bromo-terminated PEG with ibuprofen-Cs salt. The conversion of the terminal hydroxyl groups to bromo-termini was quantitative, as was the drug conjugation process, which suggests that the present synthetic method is very useful for the preparation of PEG-based prodrugs from pharmaceuticals having carboxyl functionalities. The drug-release behavior of the prodrugs was examined in both phosphate buffer (PBS, pH 7.4) and rat plasma. From the drug-release behavior in PBS, we determined that each prodrug has high storage stability. The drug-release rate was observed to be much faster in rat plasma than in buffer solution as a result of the acceleration effect provided by enzymes present in the plasma. The drug-release rate in rat plasma depends on the degree of molecular aggregation of the prodrugs, which can be changed effectively by the nature of their spacer groups or by the use of Pluronic as the polymer carrier.

• KSBB Journal
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• v.26 no.4
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• pp.283-292
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• 2011

Solid dispersion is one of well-established pharmaceutical techniques to improve the dissolution and consequent bioavailability of poorly water soluble drugs. It is defined as a dispersion of drug in an inert carrier matrix. Solid dispersions can be classified into three generations according to the carrier used in the system. First and second generations consist of crystalline and amorphous substances, respectively. Third generation carriers are surfactant, mixture of polymer and surfactants, and mixture of polymers. Solid dispersions can be generallyprepared by melting method and solvent method. While melting method requires high temperature to melt carrier and dissolve drug, solvent method utilizes solvent to dissolve the components. The improvement in dissolution through solid dispersions is attributed to reduction in drug particle size, improvement in wettability, and/or formation of amorphous state. The primary characteristics of solid dispersions, the presenceof drug in amorphous state, could be determined by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and fourier-transformed infrared spectroscopy (FTIR). In spite of the significant improvement in dissolution by solid dispersion technique, some drawbacks have limited the commercial application of solid dispersions. Thus, further studies should be conducted in a direction to improve the congeniality to commercialization.

• Polymer(Korea)
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• v.36 no.2
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• pp.149-154
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• 2012

The amphiphilic copolymer by the conjugation of biocompatible chitosan and antioxidant lipoic acid was studied as a drug delivery carrier. The amphiphilic copolymer was self-assembled to form nanoparticles in the aqueous solution. 5-Fluorouracil widely used as an anticancer drug was encapsulated inside the nanoparticles by a solid dispersion method. The degree of branching of lipoic acid on chitosan was controlled to obtain the optimal condition for the drug delivery carrier. The sizes of nanoparticles were about 250 nm by the dynamic light scattering. The encapsulation efficiency of nanoparticles were about 10%. The copolymer with 42% degree of branching showed the best performance as a drug delivery carrier.

• Journal of Pharmaceutical Investigation
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• v.5 no.4
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• pp.17-23
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• 1975

복용량이 비교적 적고, 난용성 의약품(醫藥品)으로 antirheumatism에 사용되고 있는 phenylbutazone을 macromolecule polymer로서 water soluble carrier인 polyvinylpyrrolidone과 solvent method로 1:1, 1:5, 및 1:9(w/w)의 coprecipitate를 형성(形成)시켰으며, 이들 coprecipitate의 용출 속도를 Pure drug 및 coprecipitate 형성 용매인methanol에서 재결정한 recrystallized pure drug의 그것과 측정 비교(比較)하였다. 1:1,1:5 및 1:9(w/w)의 coprecipitate는 recrystallized pure phenylbutazone보다 약 4.5배의 용출의 증가를 보였고, 이들 1:1,1:5,1:9(w/w)에서의 그 carrier의 양(量)에 따른 용출에의 영향은 거의 없었다. 시간(時間)에 대(對)한 log probit를 plot하여 구(求)한 dissolution half life, $T_{50%}$는 coprecipitate ratio 1:1(w/w)에서는 5.5분, 1:5에서는 10분, 1:9에서는 12.5분이었다.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.1-9
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• 1993

The endothelial cell of brain capillary called the blood-brain barrier (BBB) has carrier-mediated transport systems for nutrients and drugs. The mechanism of the BBB transport of basic and acidic drugs has been reviewed and examined for endogenous transport systems in BBB in WKY and SHRSP. Acidic drugs such as salicylic acid and basic drugs such as eperisone are taken up in a carrier mediated manner through the BBB via the monocarboxylic acid and amine transport systems. The specific dysfunction for the choline transport at the BBB in SHRSP would affect the function of the brain endothelial cell and brain parenchymal cell. The utilization of the endogenous transport systems of monocarboxylic acid and amine could be promising strategy for the effective drug delivery to the brain.

• Journal of Pharmaceutical Investigation
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• v.40 no.3
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• pp.181-185
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• 2010

The objective of this study was to improve the extent of drug release as well as the dissolution rate of TD49, a novel algicidal agent, via the preparation of solid dispersion (SD). Among the various carriers tested, $Solutol^{(R)}$ HS15 was most effective to enhance the solubility of TD49. Subsequently, SDs of TD49 were prepared by using $Solutol^{(R)}$ HS15 and their solubility, dissolution characteristics and drug crystallinity were examined at various drug-carrier ratios. Solubili ty of TD49 was increased significantly in accordance with increasing the ratio of $Solutol^{(R)}$ HS15 in SDs. Compared to untreated powders and physical mixtures (PMs), SDs facilitated the faster and greater extent of drug release in water. Particularly, SD having the drug-carrier ratio of 1:20 exhibited approximately 90% of drug release within 1 hr. Differential scanning calorimetry (DSC) thermograms and X-ray diffraction (XRD) patterns suggested that SDs might enhance the dissolution of TD49 by changing the drug crystallinity to an amorphous form in addition to the increased solubilization of drug in the presence of $Solutol^{(R)}$ HS15. In conclusion, SD using $Solutol^{(R)}$ HS15 appeared to be effective to improve the extent of drug release and the dissolution rate of poorly water soluble TD49.