• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.292.1-292.1
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• 2003

Purpose. To develop a new heterodisperse 650mg acetaminophen HPMC matrix tablet with biphasic sustained release profiles. Methods. Hydroxypropylmethylcellulose(HPMC) matrix tablets were prepared by wet-granulating drug with other excipients, followed by direct compression of the dried granule mixtures into tablet using a rotary tablet machine. (omitted)

• Journal of Pharmaceutical Investigation
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• 제32권3호
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• pp.199-207
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• 2002

In order to develop a sustained release formulation of bovine somatotropin (BST), which has been used to increase the body weight of oxen or the milk production of dairy cows, poly(D,L-lactide-co-glyceride)(PLGA) microspheres were made by W/O/W multiple emulsification method and solvent extraction method. Physical properties including particle size, drug entrapment, drug release, protein denaturation, and in vivo body weight increase in rats were characterized. The size of the microspheres was increased as the molecular weight of PLGA increased. When Span 65 and stearic acid during preparation were added, the size was decreased but the amount of surface protein was increased, resulting in a high loading efficiency, with fast release of BST from the microspheres. Aggregation or fragmentation of BST by SDS-PAGE during microsphere preparation and drug release study was not observed. Body weight of Sprague-Dawley's male rats was significantly increased after subcutaneous administrations of BST-loaded PLGA microspheres. There was a good correlation between in vivo weight gain and in vitro release rate of microspheres. PLGA microspheres with a high surface protein ratio could be a good candidate for the sustained delivery of BST.

• 대한치과재료학회지
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• 제44권1호
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• pp.21-31
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• 2017

The purpose of this study was to fabricate a biocompatible fluoride varnish with sustained fluoride release, and to compare it with commercial fluoride varnishes. For the experimental fluoride varnish, bis-GMA (BG) or two types of rosin (KR-610: K0, KR-612: K2) were used as bases. Either ethyl acetate or ethanol was added as solvent and 5 wt% NaF was used. 5 mg of experimental F- varnishes and 2 commercial products, Cavity shield (CS) and Flor-opal (FO), were applied on a labial surface of bovine teeth ($10mm{\times}7mm$). The amount of fluoride release was measured at 1 hr, 2 hrs, 3 hrs, 4 hrs, 8 hrs, 12 hrs, 1 day, 3 days, 5 days, 10 days, 15 days, 20 days and 30 days. MTT test was done with diluted F- varnishes using ethanol. Statistical analysis was done with one-way ANOVA and Duncan multiple range test (${\alpha}=0.05$). BG showed the highest fluoride release at 1 hr (P<0.05), while that of K0 was highest at 2 hrs (P<0.05). From 1 day to 5 days, experimental fluoride varnishes showed higher fluoride release than the commercial products (P<0.05), and there were no significant differences after 5 days (P>0.05). For MTT test, K0 and FO showed higher cell viability than other experimental groups (P<0.05), with no significant differences with K2 (P>0.05). Considering the sustained fluoride release and cell viability of the experimental rosin-based fluoride varnishes compared with commercial products, it will be appropriate for clinical application.

• Archives of Pharmacal Research
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• 제16권1호
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• pp.50-56
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• 1993

The microencapsulation of sodium naproxen with Eudragit. RS was studied by coacrtvation/phase separation process using Span 80 in mineral oil/acetone system. Various factors which affect the mciroencapsulation, e.g., stirring speed, and surfactant concentraction, Eudagit RS concentration and loading drug amounts were examined. For the evaluation of the prepared microcapsules, release rate, particle size distribution and surface appearance as well as in vivo test were carried out. The addition of n-hexane and freezing of microcapsules accelerated the hardening of microcapsules. The optimum concentration of Span 80 ti prepare the smallest microcapsules was the same value with the CMC of Span 80 in solvent system. When 1.5% (w/w) Span 80 was used, the smallest microcapsules were formed $(30.02\pm5.05\mu$ in diameter) belonging to the powder category showing smooth, round and uniform surface. The release of sodium naproxen was retarded by microencapsulation with Eudragit RS. The Eudragit RS microcapsules showed significantly increased AUC and MRT and deceased Cl/F in rabbits.

• Journal of Pharmaceutical Investigation
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• 제35권3호
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• pp.151-155
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• 2005

A drug delivery system(DDS) for practically insoluble meloxicam was developed and evaluated by dissolution study. A novel DDS is two layered system, where the first layer is consisted of gas-forming agent for an immediate release and the second layer is composed of metolose SR(HPMC) for sustained release. This bilayered tablets were manufactured by using manual single punch machine. The results of dissolution study showed an initial burst release followed by sustained release for the experimental period time. From a pharmaceutical point of view, the designed DDS for meloxicam would be informative system in terms of poorly soluble analgesic medicines.

• Journal of Pharmaceutical Investigation
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• 제29권2호
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• pp.105-109
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• 1999

The sustained release of piracetam by complexation with ion exchange resin was prepared. The complex was coated with Eudragit RS100 and their releases in vitro were conducted with various different kinds of medium solution. Dissolution rate increased as ionic strength, acidity and drug concentrations increased and reached its maximal plateau concentration within 5 min. Based on these data, The controlled release of piracetam using ion-exchange piracetam complex coated with Eudragit RS100 could be available.

• Macromolecular Research
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• 제8권6호
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• pp.253-260
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• 2000

Biodegradable wafers were prepared with poly (hydroxybutyrate-co-hydroxyvalerate) (PHBV;5, 10, and 15 mole% for 3-hydroxyvalerate) by simple heat pressing method for the sustained release of antibiotic agent, gentamicin sulfate (GS) to investigate the possibility of the treatment for osteomyelitis. The effects of hydroxyvalerate (HV) content, thickness of wafers, various types of additives such as sodium dodecyl sulfate (SDS), microcrystalline cellulose, polyvinylpyrrolidone, and hydroxypropylcellulose (HPC), and different initial drug loading ratio on the release profile have been investigated. In vitro release studies showed that different release patterns and rates could be achieved by simply modifying factors in the preparation conditions. PHBV wafers with 3 mm thickness, 10% of GS initial loading, 15% of HV content and addition of 5% of SDS and HPC were free from initial burst and a near-zero-order sustained release was observed for over 30 days. It might be suggested that the mechanisms of G5 release may be more predominant simple dissolution and diffusion of GS than erosion of PHBV in our system.

• KSBB Journal
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• 제10권4호
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• pp.461-467
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• 1995

본 연구에서는 약물 전달체(키토산, 키토산.엽, 술폰화키토산)에 prednisolone을 분산시켜 제조한 고분자 매트릭스를 poly (DL-lactide)로 피막을 형성시킨 후 pH 1.2와 pH 7.4 인산염 완충용액에서 약물 방출실험을 하였다. 약물 방출시간은 pH 1.2에서 보다 pH 7.4에서 더 지연되였으며 약물 전달체의 함유량이 증가함에 따라 약물의 방출시간도 지연되었다. 피막된 고분자 매트릭스의 종류에 따라 지연된 약물의 방출시간은 키토산의 경우가 가장 길었으 며, 술폰화키토산, 키토산.염의 순셔였다. Monolith IC 고분자 매트릭스에 비해 2배 정도의 약물의 방출 지연성을 보인 피막된 monolithic 고분자 매트럭스 가 방출조절형 제제로서 더 바람직한 것으로 관찰되었다. 이러한 제형들은 초기 급격한 약물 방출속도의 변화를 억 제 하는 sustained release pattern 제 제 임을 확인할 수 있었다.

• 한국임상약학회지
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• 제3권1호
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• pp.79-88
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• 1993

Bioequivalence(BE) test of commercially available sustained release tablets of diltiazem hydrochloride(DTZ) was performed to give some guidelines to BE test in korea in case of which drugs with low oral bioavaiiability(BA) due to substantial first-pass hepatic loss form pharmacologically active metabolites. In such cases, the pharmacologic activity after oral administration is greater than anticipated from BA data, based on chemical assay of drug alone. Therefore, this paper explores the use and meaning of area under the plasma concentration-time(AUC) data of parent and its metabolites to access BA if sustained release tablets. Normal healthy male volunteers(n=14) were randomly divided into 2 groups, and sustained release reference$(Herbesser^{(R)})$ and test$(Herben^{(R)})$ tablets of DTZ-30mg were given orally by balanced two-period cross-over dosing schedule. The plasma concentration of DTZ and and its active metabolite, desacetyldiitiazem(DAD), were determined by high performance liquid chromatography, and, $AUC_{DTZ},\;AUC_{DAD},\;AUC_{DTZ+DAD},\;C_{max}\;and\;T_{max}$ obtained. Analysis of varlance(ANOVA) showed that $AUC_{DTZ}\;and\;C_{max}$ passed the standard $(\alpha=0.05,\;1-\beta\geq0.8,\;\Delta\leq0.2)$ of BE test of korea, but $AUC_{DAD}$ was not satisfied from the standpoint of power. On the other hand, $AUC_{DTZ\midDAD}$ may be more avaliable than $AUC_{DAD}$ from the standpoint of statistics and pharmacologic equivalence.

• 한국산학기술학회논문지
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• 제16권11호
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• pp.7838-7843
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• 2015

본 논문에서는 제 2형 당뇨병의 1차 선택약으로 사용되는 메트포르민 염산염이 통상적으로 1일 1000mg~2000mg의 고용량으로 투여되고 동시에 매우 높은 수성용해도를 가지므로 1일 1회 복용을 위한 약물방출제어시스템에 다량의 서방성 부형제를 필요로 하여 제형의 크기가 커져 복용이 어려운 문제점이 있다. 따라서 이를 개선하고자 상대적으로 수성용해도가 낮은 새로운 메트포르민 산부가염을 합성하여 서방성 정제에 적용하여 메트포르민의 방출을 확인하고자 하였다. 이를 위해 메트포르민 염산염을 원료로 하여 NaOH하에서 메트포르민 base를 만들고 여기에 산부가염을 반응시켜 6개의 새로운 메트포르민 산부가염들을 합성하였다. 또한 이들의 수성용해도를 측정하여 메트포르민 염산염에 비해 현저히 낮은 수성용해도를 가지는 메트포르민 스테아린산염을 확인하였고 메트포르민 서방성 제형에 적용하여 실제 약물의 방출제어에도 용출시험 결과, 12시간에서 약 2배의 약물방출제어 효과를 확인하였다. 결론적으로 새로운 메트포르민 산부가염을 통해 서방성 부형제의 양을 줄여 제형의 크기를 줄임으로써 보다 높은 환자의 복약순응도를 기대할 수 있을 것이다.