• Journal of Pharmaceutical Investigation
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• 제27권3호
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• pp.213-217
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• 1997

The present sustained-release terfenadine-pseudoephedrine HCl dosage form was the core tablet composed of outer (fast-release) layer containing 60 mg of terfenadine and l0mg of pseudoephedrine HCl, and inner (sustained-release) layer containing 110 mg of pseudoephedrine HCl. The purpose of this study was to investigate the possibility of formulating the terfenadine-pseudoephedrine HCl double-layered tablet which was bioequivalent to the core tablet. Its sustained-release and fast-release layer were formulated with disintegrating agents and polymers, respectively, varying with their kinds and amounts. The comparative dissolution test of double-layered and core tablet was carried out at pH 1.2, 4.0 and 6.8, leading to select composite of double-layered tablet whose dissolution pattern was similar to that of core tablet. It was composed of fast-release layer containing 60mg of terfenadine. 10 mg of pseudoephedrine HCl, sodium bicarbonate, microcrystalline cellulose and sodium starch glycolate, and sustained-release layer containing 110 mg of pseudoephedrine HCl and ethylcellulose/hydroxypropyl methylcellulose) (110/30 mg/tablet).

• Fibers and Polymers
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• 제7권1호
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• pp.20-25
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• 2006

The alkaline dissolution behavior of sea-island type polyarnide microfibers were successfully monitored using a cationic dye staining method. Weight reduction behavior of the alkali-treated microfiber fabrics and the treated fabrics stained with cationic dye were investigated in a comparative manner. The termination of dissolution monitored by both methods was also confirmed by scanning electron microscopy.

• Journal of Pharmaceutical Investigation
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• 제37권3호
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• pp.193-196
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• 2007

This study aimed to evaluate and develop $Eudragit^{(R)}$-coated pellets based on the dissolution using the paddle method. As coating materials, two types of $Eudragit^{(R)}$ were applied to obtain either sustained release form or fast released form. The dissolution test was carried out in phosphate buffer solution (pH 6.5) at $37^{\circ}C$, 100 rpm. In order to develop a sustained release preparation containing felodipine, a comparative dissolution study was done using commercial product as a control. The dissolution at 30 min of felodipine from $Eudragit^{(R)}$ RS or RL-coated pellets were 0.96% and 99.65, respectively. The weight ratio of $Eudragit^{(R)}$ RL pellets to RS pellets altered the dissolution rate, but did not optimize the dissolution rate. However, the sustained dissolution of felodipine from pellets was optimized by varying the coating ratios of $Eudragit^{(R)}$ RS. It is suggested that the coating ratio of pellets is the main factor which controls dissolution rate. Taken together, $Eudragit^{(R)}$ RS 30D-coated pellets showed the most comparable dissolution rate pattern to commercial product, $Splendil^{(R)}$. This sustained release pellets for oral delivery system of felodipine was simply manufactured, and drug release behavior was highly reproducible.

• 한국식품위생안전성학회지
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• 제37권2호
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• pp.114-120
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• 2022

본 연구에서는 체내에서 비타민 C의 지속성을 나타내기 위해 성분의 용출을 조절하는 기술이 적용된 용출조절형 비타민 C 제품과 일반적인 속방형 비타민 C 제품의 비교용출 실험을 진행하여, 일반적인 속방형 제품과 용출조절형 제품 간의 용출 양태를 비교분석 하였다. 비타민 C 정제들의 용출률을 확인하기 위해 '대한약전(제2020-88호)', '경구용의약품의 용출규격 설정 가이드라인'의 용출시험법, '건강기능식품의 기준 및 규격 고시(제2020-63호)'에 근거한 HPLC 함량시험을 수행하여 시간별 용출률을 분석하였다. 분석 결과 속방형 비타민 C 제품은 45분 이후 100% 용출이 이루어진 반면 용출조절형 비타민 C 제품은 480분(8시간) 이후에 100% 용출이 나타났으며, 용출조절형 비타민 C 제품의 60분에서의 용출률이 속방형 비타민 C 제품에 비해 더 느리게 나타나는 것을 확인하였다. 이러한 결과를 바탕으로 비타민 C를 주성분으로 한 용출조절형 정제의 개발 및 용출분석이 가능함을 확인하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.53-56
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• 2010

In this study, we conducted an impact assessment of the amount of volatile organic solvents addition on hybrid water-proofing system of urethane waterproof coating material and modified asphalt sheet. Also, we conducted a comparative assessment of whether modified asphalt sheet is dissolved or not and oil leakage by dissolution in order to perform a comparative analysis of characteristics of the impact on modified asphalt sheet according to the volatility of volatile organic solvents included in urethane waterproof coating material. The test was carried out by adding the same amount of organic solvents into each experimental group which is subject to volatility and non-volatility of organic solvents, respectively. The results of the test showed that in both experimental groups modified asphalt sheet was dissolved when adding over 10 percent of organic solvents regardless of volatility, and oil leakage observed only in the experimental group subject to volatility.

• Journal of Pharmaceutical Investigation
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• 제38권6호
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• pp.381-385
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• 2008

Isosorbide dinitrate is an oral assiatant therapy agent of angina pectoris, myocardial infarction and congestive heart failure. The objective of this study was to formulate sustained release containing isosorbide dinitrate and assess their formulation variables. Pellets were prepared by fluid bed process and consist of drug layer and membrane layer. The pellets were coated with ethylcellulose along with $5{\sim}15%$ of plasticizer such as triacetin and diethyl butylrate. In vitro evaluation study was performed by comparative dissolution test between test and reference isosorbide dinitrate preparation. We could prepare sustained pellets of isosorbide dinitrate by fluid bed process which were reduced process time and had high content. The pellet coated with 1% ethylcellulose and triacetin(l5%) had a similar dissolution behavior compare to reference isosorbide dinitrate preparation controlling initial dissolution and those of dissolution at 30 min were 17.25 and 17.09%, respectively. Difference factor and similarity factor were $0{\sim}15$ and $50{\sim}100$ and there was no significant difference in bioequivalence between formulations. It might be concluded that our sustained release pellet of isosorbide dinitrate could be an alternatively delivery system to reference drug preparation.

• 에너지공학
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• 제13권4호
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• pp.301-310
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• 2004

이산화탄소를 해양에 대량으로 처리하는 기술이 지구온난화현상을 완화시키는 기술의 하나로 알려져 있다. 따라서 본 연구에서는 이산화탄소를 해수에 용해시키기 위해서 중층심해 1,000m와 1,500m 깊이에 분사된 액체 이산화탄소의 용해거동을 계산한 결과, 해저 약 500m 깊이에서 이산화탄소는 액체에서 기체로 상변화를 일으키며, 이산화탄소와 해수의 접촉면에 생성되는 하이드레이트는 용해에 장애물로 작용하였다. 또한 움직이는 배에서 이산화탄소를 분사하는 방법이 고정파이프라인에서 분사하는 방법보다 용해에 더 효과적이었다.

• Journal of Pharmaceutical Investigation
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• 제32권3호
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• pp.185-190
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• 2002

To improve the solubility of poorly water-soluble drug and to develop a sustained release tablets, the need for the technique, the formation of solid dispersion with polymeric materials that can potentially enhance the dissolution rate and extent of drug absorption was considered in this study. The 1:1, 1:4, and 1:5 solid dispersions were prepared by spray drying method using PVP K30, ethanol and methylene chloride. The dissolution test was carried out at in phosphate buffer solution at $37^{\circ}C$ in 100 rpm. Solid dispersed drugs were examined using differential scanning calorimetry and scanning electron microscopy, wherein it was found that felodipine is amorphous in the PVP K30 solid dispersion. Felodifine SR tablets were prepared by direct compressing the powder mixture composed of solid dispersed felodipine, lactose, Eudragit and magnesium stearate using a single punch press. In order to develop a sustained-release preparation containing solid dispersed felodipine, a comparative dissolution study was done using commercially existing product as control. The dissolution rate of intact felodipine, solid dispersed felodipine and its physical mixture, respectively, were compared by the dissolution rates for 30 minutes. The dissolution rates of felodipine for 30 minutes from 1:1, 1:4, 1:5 PVP K30 solid dispersion were 70%, 78% and 90%. However, dissolution rate offelodipine from the physical mixture was 5% of drug for 30 minutes. Our developed product Felodipine SR Tablet showed dissolution of 17%, 50% and 89% for 1, 4, and 7 hours. This designed oral delivery system is easy to manufacture, and drug releases behavior is highly reproducible and offers advantages over the existing commercial product. The dissolution rate of felodipine was significantly enhanced, following the formation of solid dispersion. The solid dispersion technique with water-soluble polymer could be used to develop a solid dispersed felodipine SR tablet.

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 NEW STRATEGY FOR DRUG DEVELOPMENT IN POST-GENOMIC ERA(대한약학회)
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• pp.265.2-265.2
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• 2000

• Archives of Pharmacal Research
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• 제24권6호
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• pp.568-571
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• 2001

The purpose of this work was to study the effect of storage time and temperature on the in vitro release kinetics of a commercial sustained-release dosage form of theophylline, at different pHs of the dissolution medium. The formulation was stored at $35^{\circ}C$ for 16 months and at $45^{\circ}C$ for 8 months, with a relative humidity of 60%. The in vitro release tests were performed at pHs 2, 4, 6 and 7.4. The mean values of the transport coefficient n, were close to 0.5 in all the conditions tested, which indicates that the transport system is not modified after storage of the formulation at $35^{\circ}C$ and $45^{\circ}C$. The mean values of the dissolution rate constant ranged from 0.036 to 0.043 $min^{-n}$, under all the conditions tested. Significant differences (${\alpha}=0.05$) were found between pHs 2, 4 and 6, 7.4 for all the model-independent parameters studied. When the formulation was kept at $35^{\circ}C$ for 16 months, the mean percentage of drug dissolved at 8 hours was 25.61% (pHs 2, 4) and, 36.12% (pHs 6, 7.4), representing a 26% and 24% reduction, respectively. Simitar results were obtained after storing the formulation at $45^{\circ}C$ for 8 months, corresponding to 33.3% (pHs 2, 4) and, 22.5% (pHs 6, 7.4) diminution, respectively. The values of the similarity factory $f_2$, obtained were lower than 50, which indicates the lack of similarity among the dissolution profiles, after storing the formulation under the experimental Conditions tested.