• YAKHAK HOEJI
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• v.23 no.2
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• pp.81-94
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• 1979

Rifampicin-polyvinylpyrrolidone coprecipitates were prepared by the solvent method to increase the solubility and dissolution rate, thereby improving absorption of rifampicin. It was found that the solubility and dissolution rate were greater with the 1 : 5 (w/w) coprecipitate than with the pure drug, physical mixtures or coprecipitates of any other ratio of the two components. The blood concentration data in non-fasted rats showed that the extent of absorption of rifampicin were significantly enhanced following the oral administration of the 1 : 5 coprecipitate; The area under the serum concentration curve (0-8hr) was 1.3 times greater with the 1 : 5 coprecipitate than with the pure drug. The blood concentration reached its peak (4. 38$\pm$1.36mcg/ml) within two hours in the case of oral administration of the 1 : 5 coprecipitate and, on the other hand, it reached the maximum (3.77$\pm$0.90mcg/ml) after four hours of oral administration of the pure drug. It was observed that there was no significant difference between the 1 : 5 coprecipitate and the pure drug in the extent and rate of absorption of rifampicin when fasted rats were used. When the 1 : 5 coprecipitate was orally administered to human subjects 20 minutes after meal, it was found that the blood concentration reached the maximum after one hour; in the case of the pure drug, it reached its peak after four hours.

• Journal of Pharmaceutical Investigation
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• v.28 no.4
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• pp.249-255
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• 1998

Solid Lipid Nanoparticle(SLN), one of the colloidal carrier systems, has many advantages such as good biocompatibility, low toxicity and stability. In this paper, the effects of drug lipophilicity and surfactant on the drug loading capacity, particle size and drug release profile were examined. SLNs were prepared by homogenization of melted lipid dispersed in an aqueous surfactant solution. Ketoprofen, ibuprofen and pranoprofen were used as model drugs and tweens and poloxamers were tested for the effect of surfactant. Mean particle size of prepared SLNs was ranged from 100 to 150nm. The drug loading capacity was improved with the most lipophilic drug and low concentration of surfactant. Particle size and polydispersity of SLNs were changed according to the used lipid and surfactant. The rates of drug release were controlled by the loading drug and surfactant concentration. SLN system with effective drug loading efficiency and proper particle size for the intravenous or oral formulation can be prepared by selecting optimum drug and surfactant.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1333-1336
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• 2014

Expanded polytetrafluoroethylene (ePTFE) grafts have been used as vascular access for many patients suffering from end stage renal disease. However, the vascular graft can cause significant clinical problems such as stenosis or thrombosis. For this reason, many studies have been performed to make drug eluting graft, but initial burst is major problem in almost drug eluting systems. Therefore we used biodegradable polymer to reduce initial burst and make sustained drug delivery. The ePTFE grafts were dipped into a paclitaxel-dissolved solution and then PLGA-dissolved solution was passed through the lumen of ePTFE. We analyzed whether the dose of paclitaxel is enough and the loading amount of PLGA on ePTFE graft increases according to the coating solution's concentration. Scanning electron microscope (SEM) images of various concentration of PLGA showed that the porous surface of graft was more packed with PLGA by tetrahydrofuran solution dissolved PLGA. In addition, in vitro release profiles of Ptx-PLGA graft demonstrated that early burst was gradually decreased as increasing the concentration of PLGA. These results suggest that PLGA coating of Ptx loaded graft can retard drug release, it is useful tool to control drug release of medical devices.

• Journal of Pharmaceutical Investigation
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• v.30 no.1
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• pp.33-37
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• 2000

One of the methods to increase the solubility of a drug is to use complexation with a cyclodextrin. Due to the hydrophobic nature of the interior cavity of the cyclodextrin, it has been known that undissociated lipophilic drugs can be included within the cyclodextrin by hydrophobic interaction. Recently, inclusion of hydrophilic or dissociated form of a drug has been investigated. In this study, the synergism of pH and complexation with $hydroxypropy-{\beta}-cyclodextrin\;(HP\;{\beta}\;CD)$ to increase the solubility of two oxicam derivatives was investigated. In addition, the effect of partition coefficient of dissociated and undissociated form of the drug on the extent of complexation with HP ${\beta}$ CD was studied. The solubility was measured by equilibrium solubility method. The solubility of tenoxicam and piroxicam increased exponentially with an increase in solution pH above the pKa of the drug in the presence and absence of HP ${\beta}$ CD. The solubility of the drugs increased linearly as a function of HP ${\beta}CD$ concentration at fixed pH. Although the stability constant of ionized species is less than that of the unionized species, the concentration of the ionized drug complex is greater than that of the unionized drug complex due to higher concentration of ionized species at pH 7.3.

• The Journal of Internal Korean Medicine
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• v.15 no.1
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• pp.45-59
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• 1994

The present experiments were designed to investigate the effect of Ijntang, Sagoonjatang, and Yuggoonjatang on the hyperlipidemia induced rabbit. In order to control the precise chemical and physical condition, the experimental rabbits were supplied with calory limited food. The Hyperlipidemia rabbits were induced by oral administration of cholesterol (250mg/kg) for 4 weeks. The results were as followings : 1. The hyperlipidemia (control) group increased the concentration of serum glucose to $204.1{\pm}2.63\;mg/dl$ at the 4th. week, however, the other drug administrated groups such as Ijintang, Sagoonjatang, and Yuggoonjatang decreased significantly. 2. The control group increased the concentration of serum totalcholesterol to $299.0{\pm}4.18\;mg/dl$ at the 4th. week, however, the other drug administrated groups Ijintang, Sagoonjatang, and Yuggoonjatang decreased significantly. 3. The control group increased the concentration of serum total lipid to $429.1{\pm}1.72\;mg/dl$ at the 4th. week, however, the other drug administrated groups such as Ijintang, Sagoonjatang, and Yuggoonjatang decreased significantly. 4. The control group increased the concentration of serum triglyceride to $149.3{\pm}3.01\;g/dl$ at the 4th. week, however, the other drug administrated groups such as Ijintang, Sagoonjatang, and Yuggoonjatang decreased significantly. 5. The control group increased the concentration of serum HDL-cholesterol to $83.0{\pm}1.09$\;mg/dl$ at the 4th. week, and, the other drug administrated groups such as Ijintang, Sagoonjatang, and Yuggoonjatang increased significantly. 6. The lipid deposition to the aortic endothelium decreased more at the Yuggoonjatang group than the other groups. According to the above experimental results, Yuggoonjatang is assumed to have a more curative effect against hyperlipidemia than the other drug such as Ijintang and Sagoonjatang.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.198-203
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• 1999

Loxoprofen-Na (sodium 2-〔4-(2-oxocyclopentylmethyl)pheny)propionate dihydrate) is a potent analgesic drug. We developed loxoprofen-Na plasters to extend duration time of analgesic activity and to reduce side effect on gastrointestinal tract. Analgesic effect of Loxoprofen-Na plasters was investigated. Loxoprofen-Na plaster had good analgesic effect in rat paw pressure test, Tail-flick latency test and acetic acid-induced writhing test. Also, it had anti-inflammatory effect on carrageenan-induced rat hind paw edema. In pharmacokinetic study of Loxoprofen-Na, plasters dosage form showed that plasma drug concentration was prolonged up to 14 hours. So, we can conclude that loxoprofen-Na plasters, when applied on skin, will be a new type of drug for controlling the various local pain or inflammation.

• Biomolecules & Therapeutics
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• v.15 no.2
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• pp.73-77
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• 2007

N,N-Dimethyl-D-ribo-phytosphingosine (DMPH) is an N-methyl derivative of sphingosine. In the present paper, we studied effects of DMPH on intracellular Ca$^{2+}$ concentration, pH, glutamate uptake, and cell viability in human 1321N1 astrocytes. DMPH increased intracellular Ca$^{2+}$ concentration and cytosolic pH significantly in a dose-dependent manner. DMPH also inhibited glutamate uptake by 1321N1 astrocytes. Finally, treatment of cells with DMPH for 24 h reduced viability of cells largely and concentration-dependently. In summary, DMPH increased intracellular Ca$^{2+}$ concentration and pH, inhibited glutamate uptake and evoked cytotoxicity in 1321N1 astrocytes. Our observations with DMPH in the 1321N1 astrocytes would enhance understanding of DMPH actions in the brain.

• Archives of Pharmacal Research
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• v.9 no.2
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• pp.87-91
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• 1986

In attempt to develop a drug delivery system using serum albumin microspheres, bovine serum albumin microspheres containing antitumar agent. Cytarabine, were prepared. The shape, surface characteristics, size distribution, behavior of in vivo distribution, drug release behavior, and degradation of albumin microsphers in animal liver issue homogenate and proteolytic enzyme were investigated. The shape of albumin microspheres was spherical and the surface was smooth and compact. The size distribution of the albumin microspheres was effected by dispertion forces during emulsification and albumin concentration. Distribution of albumin microspheres after imtravenous administration in rabbit was achieved immediately. In vitro, albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin concentration ratio and size distribution. After drug release test, the morphology of albumin microspheres was not changed. Albumin microsphere matrix was degraded by the animal liver issue homogenate and proteolytic enzyme. The degree of degradation was affected by heating temperature.

• Archives of Pharmacal Research
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• v.8 no.3
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• pp.159-168
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• 1985

In attempt to develop a drug delivery system using serum albumin microspheres, bovine serum albumin microspheres containing antitumor agent, cytarabine, were prepared. The shape, surface characteristics, size distribution, behavior of in vitro distribution, drug release behaior, and degradation of albumin microspheres in animal liver tissue homogenate and proteolytic enzyme were investigated. The shape of albumin microspheres was spherical and the surface was smooth and compact. The size distribution of the albumin microspheres was affected by dispersion forces during emulsification and albumin concentration. Distribution of albumin mirospheres after intravenous administration in rabbit was achieved immediately. In vitro, albumin microsphere matrix was so hard that it retained most of cytarabine except initial burst during the first 10 minutes, and the level of drug release during the initial burst was affected by heating temperature, drug/albumin concentration ratio and size distribution. After drug release test, the morphology of albumin micropheres was not changed. Albumin microsphere matrix was degraded by the rabbit liver tissue homogenate and proteolytic enzyme. The degree of degradation was affected by heating temperature.

• Archives of Pharmacal Research
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• v.17 no.4
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• pp.240-243
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• 1994

Release rates of flurbiprofen from transdermal gels made of poloxamer 407 were evaluated using a membraneless diffusion cell in order to study the effects of formulation variables on flurbiprofen release such as poloxamer 407 (17.5-25%) drug (0.1-1.0%), ethanol (10-20%), PG or PEF 300 (5-15%) concentrations and gel pH(3-7). Isopropyl myristate was employed as a receptor medium for the drug released from the gel. The diffusion coefficient of flurbiprofen decreased linearly as the amount of poloxamer 407 and the drug in the gel increased. The release rate of flurbiprofen was gel increased. The The addition of more ethanol in the gel increased the drug release, resulting from the increase of the thermodynamic activity of the drug in the aqueous phase of the gel. However, the concentration effects of PG and PEG 300 on the release rate of flurbiprofen were negligible over the concentration range used.