• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.25 no.4
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• pp.304-310
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• 1999

This study was designed to find the effect of Minocycline loaded microcapsule applied locally to tissue by measuring drug concentration in tissue and serum by HPLC and to achieve optimal drug delivery system and duration to a specific target site. Control group were administrated minocycline intramuscularly twice a day with $0.2{\mu}g/100g$ for 1 to 10 days. In experimental group, surgical wound was created on Rt. cheek and then minocycline loaded microcapsule was applied into the space between superficial and deep layer of masseter muscle. Animals were sacrificed at 1, 3, 5, 7, 10 days after initial administration, blood was obtained from heart and right masseter muscle was excised. Blood sample was centrifuged at 3000rpm for 15min. Tissue sample was homogenized, left at room temperature for 48hr and centrifuged at 4000g for 5min. Supernatant was completely dried and dissolved in distilled water. Analysis was conducted using a ${\mu}Bondapack$ C18 column. The mobile phase was 0.2M Ammonium Oxalate/0.1M EDTA/DMF=11/4/5 solution, which was injected into the column and detected with photodiode detector at 344nm wavelength. The results were as follows : 1. This method was reliable, could be replicated and suitable for minocycline analysis in tissue as well as serum. 2. In tissue, concentration of minocycline of experimental group was higher than that of control group for 5days. 3. Except 1 day, concentration of minocycline in serum of experimental group was lower than that of control group. 4. Concentration of minocycline in tissue was much higher than that in serum. From these results, minocycline loaded microcapsule might be effective tool for local drug delivery system might be useful for treatment of infections of oral and maxillofacial region and management of infected surgical wound, minimizing systemic effects.

• Journal of Pharmaceutical Investigation
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• v.22 no.2
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• pp.77-96
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• 1992

In recent years intranasal administration of drugs has received great attention as a convenient and efficent method of drug delivery because of its potential to improve the systemic effect of substances with a poor oral bioavailability. In addition to offering advantages such as rapid absorption, fast onset of action and avoiding the first -pass effect, it provides for delivery of drugs from very lipophilic drugs such as steroids to polar and hydrophilic drugs such as peptides and proteins. However, little is still known about the nature of various barriers existing in the nasal mucosae as well as mechanism by which these molecules are absorbed. This review article therefore intends to discuss nasal physiology, experimental methods and evaluation of absorption from the nasal cavity, factors influencing nasal absorption, mechanism of nasal absorption, approaches to improve the residence time and to obtain the sustained-release effect of intranasally administered drugs, promoters and mechanism for the enhancement of nasal absorption, Several examples for intranasal delivery of various systemically effective drugs will be reviewed and illustrated. Drug metabolism in the nasal mucosae and problems associated with intranasal administration of drugs will be also discussed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.516-521
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• 2005

Drug delivery to the lymphatic system may be important in terms of the treatment with lymphatic involvement, such as tumor metastases and immunization. Especially, drug transport via the intestinal lymphatics after oral administration has been attracted lots of interests. The purpose of this study was to prepare cyclosporin A (CSA)-loaded liposomes, with different characteristics, and evaluate their mucoadhesivity. Three liposome preparations were formulated: cationic stearylamine liposomes (SA-Lip), anionic phosphatidylserine liposomes (PS-Lip), Polymer (chitosan)-coated liposomes (CS-Lip), and characterized. The liposome preparations were found to be spherical in shape, with PS-Lip being the smallest. The liposome preparations exhibited entrapment efficiencies in the order: PS-Lip $(52.5{\pm}2.9%)$ > SA-Lip $(48.8{\pm}3.3%)$ > CS-Lip $(41.7{\pm}4.2%)$. Finally, mucoadhesive tests were carried out using rat intestine, with SA-Lip (67%) showing the best adhesive rate of the three preparations (PS-Lip: 56%, CS-Lip: 61%). These results suggest that a positive charge on the surface of drug carriers may be an important factor for the intestinal drug delivery.

• KSBB Journal
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• v.26 no.3
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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.

• Journal of Preventive Medicine and Public Health
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• v.14 no.1
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• pp.3-12
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• 1981

To identify the changes in professional care patterns after the introduction of medical insurance in Korea, professional care in hospitals and clinics of two succeeding years were compared. The hospitals and clinics selected for this study were those which located in Seoul city. Hospitals were classified into 3 categories: university hospital, general hospital and hospital. The diseases selected for this study were acute appendicitis and normal delivery. They were selected because their disease courses are considered to be fairly stable. The variables used for this study were length of stay, total hospital costs, costs of each components of cares. The information used for this study was obtained from the official forms requested by the medical facilities to the Korea Medical Insurance Corporation. The two periods studied were 3 months of each year from March 1st to May 31st in 1979 and 1980, The total number of normal delivery studied was 289 in 1979, 301 in 1980 respectively and the acute appendicitis was 92 and 111 respectively. In order to compare the quantity of medical care between 2 study periods the insurance price scores of 1979 were converted to prices of 1980. For statistical test of difference between 2 periods T-test and Welch's test were used. The result of the study were briefly summarized in below. 1. No significant difference was observed in the average length of stay of both disease between two study periods in all types of hospitals. 2. No significant difference was observed in the average total hospital costs of both diseases in all types of hospital, but in the private clinic the average clinic costs was rather decreased significantly in 1980. 3. More cost decrease were seen than cost increase in 1980 in all types of facilities, More cost changes by items were seen in acute appendicitis than in normal delivery between two study periods. The total hospital costs can be devided into 2 portions: charges for drug and material and for physician. In normal delivery, costs for physician's charges was significantly decreased in almost all the hospitals and costs for drug and material were not changed significantly in all the hospitals in 1980. In the university hospitals, however, the costs for drug and material were increased significantly in 1980. The cost decrease for physician's charge were mainly due to the decrease in the costs of laboratory test, treatment and physical therapy. The increase in the costs for the drug and material in the university hospitals was mainly due to the increase in the cost for drugs for oral administration and injection. 4. The proportion of components of medical care in the hospital has not been changed significantly, however, the cost for injection in normal delivery was characteristically increased in 1980 in all hospitals studied. In general the proportion of the costs for drug and material was tended to increase and the costs for physician was tended to decrease in 1980. The increase in the costs for drug and material were considered to be due to increase in the cost for drugs for oral administration and injection. The decrease in the costs for physician were due to decrease in the costs of laboratory test, treatment and physical therapy. Above mentioned changes in hospital and clinic care patterns are considered to be mostly influenced by the review criteria set by the K.I.C. for the assessment of the fee request made by clinics and hospitals.

• Journal of Pharmaceutical Investigation
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• v.40 no.spc
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• pp.103-112
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• 2010

Pellets, which are multiple-unit dosage systems, have the several therapeutic advantages over single-unit dosage systems in oral drug delivery. This review focuses on the current status and explores extrusion-spheronization technique with special attention to controlled-release application of pellets including coated pellets for delayed release formulations, coated pellets for colon delivery, coated pellets for sustained drug delivery, sustained-release matrix pellets, pellets compressed into tablets, bioadhesive pellets, floating pellets, and pelletization with solubilization techniques.

• Advances in materials Research
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• v.9 no.2
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• pp.109-114
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• 2020

The purpose of this study was to observe the trend of compounds release from acrylic resin oral prosthesis when used for drug delivery as well as a restoration. In this study, 10 specimens of heat-cured polymethylmethacrylate material were prepared and loaded with methylene blue biological stain. The specimens were then submerged in vials with 5 ml distilled water for 24 hours. The extraction procedure continued for 4 days, each day the specimens were immersed in another 5 ml distilled water vial. All extracted solutions were analyzed by visible light spectroscopy for absorbance comparison. The statistical results showed that the absorbance values were significantly different in the first day of extraction than the following days. However, there was no statistical difference among the 2^nd, 3^rd and 4^th days of extraction. Biological stain loading to acrylic resin at the mixing stage, and then after extraction in distilled water, showed a burst release during the first day followed by a constant release during the following few days.

• Journal of Pharmaceutical Investigation
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• v.35 no.3
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• pp.157-163
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• 2005

The pellets with multiple drug release system (MDRS) of Diltiazem. HCl which consist of immediate drug release layer, drug reservoir layer and controlled release rate membrane, were prepared by using CF-Coater. As main factors for more effective MDRS of Diltiazem. HCl, ethylcellulose was used for the controlling drug release rate, and diethylphthalate was used for plasticizer, respectively. In vitro evaluation study was performed by comparative dissolution test between our test MDRS and reference Diltiazem. HCl preparation. The physical tests were performed using FT-IR and SEM. In vivo evaluation was also performed by observing the behavior of a plasma drug concentration after oral administration. The bioavailability was determined by analyzing the blood sample after oral administration to healthy, male volunteers once a day. As a result, there were no significant differences in bioequivalence parameters $(AUC_{\infty},\;C_{max},\;t_{1/2})$ between two systems. It might be concluded that our MDRS of Diltiazem. HCl could be an alternative delivery system to reference drug preparation.

• Journal of Pharmaceutical Investigation
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• v.30 no.4
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• pp.253-258
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• 2000

In order to design the oral vaccine delivery system, we prepared the alginate micro spheres containing GFP (green fluorescent protein) as a model drug by spray method. To optimize the preparation conditions of microspheres, we investigated the effects of various parameters including nozzle pressure, nozzle opening angle, and concentrations of sodium alginate and calcium chloride. The prepared microspheres were evaluated by measuring their sizes, loading efficiency, and morphology. The particle size of microspheres was affected by the concentration of sodium alginate and calcium chloride, nozzle pressure, and nozzle opening angle. As the concentration of sodium alginate increased, GFP loading efficiency and particles size of microsphere also increased. However, it was observed to be difficult to spray the sodium alginate solution with concentration greater than 1.5% (w/v), due to high viscosity. The pressure over $3\;kgf/cm^2$ didn't affect the size of particles. As a result, the spraying method enabled us to prepare microspheres for oral vaccine delivery system. In this study, microspheres prepared with 1% (w/v) sodium alginate had greater loading efficiency and better spherical shape.

• Journal of Pharmaceutical Investigation
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• v.39 no.2
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• pp.111-115
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• 2009

The pharmacokinetics of cyclosporin A (CsA) after single and multiple oral dosing of new CsA self-micro-emulsifying drug delivery system (SMEDDS) in dogs were estimated. A single dose study was performed following a two-way crossover design against six dogs with reference SMEDDS. For a multiple dose study, three dogs were allocated for each drug, and 100 mg of drug was administered daily for 6 days. Whole blood concentration of CsA was analyzed by radio-immunoassay. Both drug showed identical blood concentration profiles in both studies, and no statistical difference was detected in pharmacokinetic parameters. The relative bioavailabilities of test SMEDDS were 91.4% and 89.1%, respectively, in the single dose study and the last day of multiple dose study. Especially, multiple dose study proved the good relationship between C-0/C-2 and AUC for reference SMEDDS, which is an indispensable part of therapeutic drug monitoring. These results suggest newly formulated CsA SMEDDS possibly shows identical pharmacokinetics and pharmacodynamic behaviors in clinical trials.