• 한국유통학회:학술대회논문집
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• 한국유통학회 2005년도 춘계학술대회 발표논문집
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• pp.87-110
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• 2005

지금까지의 관계해지에 관한 연구들은 관계해지의도를 최종 결과변수로 간주하여 연구를 수행하였으며, 관계해지의도가 형성된 이후에 관해서는 연구된 바가 전혀 없었다. 즉, 관계해지의도를 완전한 관계해지와 동일시함으로써 관계해지의도의 형성으로부터 일어나는 관계해지의 모습을 간과한 문제점을 가지고 있었다. 본 연구는 이에 대한 문제점을 해소하고 관계해지의도가 형성된 후에 어떤 경로를 통해 완전한 관계해지로 나아가는 지를 알아보기 위한 최초의 시도로써 수행되었다. 즉, 관계해지의도가 형성된 이후부터 완전한 관계해지가 일어나기 전까지의 영역을 대상으로 하여 관계해지의도의 결과변수들이 기회주의의 증가와 거래특유투자의 감소, 그리고 협력의 감소임을 밝히고 관계해지의도와 결과변수들 간의 관계를 제시함으로써 관계해지의도로부터 완전한 관계해지로 이루어지는 과정을 실증적으로 살펴보았다. 국내신문사(판매자)와 신문지국(구매자)의 관계에서 신문지국의 관점을 대상으로 설문조사를 수행하여 실증분석을 한 결과, 본 연구에서 제시한 5개의 가설들이 모두 지지되었다. 즉, 관계해지의도를 가지게 된 주체는 기회주의가 증가되고 거래특유투자를 감소시킴으로써 판매자와의 협력이 붕괴되는 과정을 통해 완전한 관계해지로 나아감을 밝혔다. 마지막으로, 본 연구의 이론적 공헌점들 및 관리적 시사점들이 논의되었고, 연구의 한계점들 및 향후의 연구방향들이 제 시 되었다.

• 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.

• 한국임상약학회지
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• 제1권1호
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• pp.15-21
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• 1991

This study was attempted to investigate the dissolution rate and bioavailability of commercially available furosemide preparations. A. B. and C. The dissolution test was conducted in an artificial gastric juice using the basket method. and furosemide (40 mg) was administered orally to 8 normal volunteers by cross-over design. The results were as follows: the AUC and dissolution rate in 100 min ($D_{100\;min}$) were higher in order of preparations. A > C > B. But the peak concentration. time to reach peak concentration $(T_{max})$, and mean dissolution time (MDT) were in order of preparations. C > A > B. There were significantly linear correlations between the AUC and the $D_{100\;min}$, and between the $T_{max}$ and the MDT. From the results of this experiment. it can be concluded that commercially available preparations bioavailability of furosemide, which may be predicted from the dissolution rate.

• Journal of Pharmaceutical Investigation
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• 제23권1호
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• pp.55-59
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• 1993

Dissolution of mucosal adhesive tablets prepared with two polymers using hydroxypropylcellulose-H (HPC) and carbopol 934 (CP) was tested. Adhesive tablets containing HPC/CP and brilliant blue FCF (BB) were prepared from direct compression. Three factors of polymer ratio (HPC:CP), BB content and compression force were chosen as important factors of preparation and factorial analysis for these factors was carried out. Eight kinds of formulations from different combinations of three factors were prepared and dissolution test in pH 6.8 phosphate buffer solution was performed. Dissolution rate was significantly affected by HPC:CP ratio and BB content, but was not affected by compression force.

• Journal of Pharmaceutical Investigation
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• 제19권1호
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• pp.1-7
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• 1989

Coprecipitates of ibuprofen (IPF)-sodium deoxycholate (DC-Na) were prepared at various mixing ratios of IPF to DC-Na. X-ray diffraction measurments indicated that IPF in 1:3 and 1:5 IPF-DC-Na coprecipitate did not exist in the crystal form, however in the 1:8 coprecipitate, IPF remained its crystalline form. The dissolution rate was tested in pH 7.4 phosphate buffer by the paddle method of dissolution test of KP V. The dissolution rates of IPF from 1:1, 1:3, 1:5, 1:8 and 1:10(w/w) IPF-DC-Na coprecipitates and physical mixtures were compared with that of IPF alone. It was found that the dissolution rate of 1:5(w/w) coprecipitate was greater than that of pure IPF, coprecipitate and physical mixture at any other ratios of the two components. The concentration of IPF released from the IPF-DC-Na coprecipitates reached a plateau within 10 min, and thereafter gradually decreased indicating that IPF released from the coprecipitate was recrystallized due to the transient supersaturation.

• 분석과학
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• 제23권4호
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• pp.389-394
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• 2010

유도결합플라즈마 원자방출분광법 (ICP-AES)을 이용한 모려 (Ostrea gigas) 칼슘의 함량 및 용출 시험 방법을 개발하고 검증하였다. 개발된 분석방법을 사용하여 모려의 총 칼슘 함량을 측정하고, 탄산칼슘 다형 및 칼슘염 조성의 차이에 의해 발생할 수 있는 모려 칼슘의 용출 특성을 평가하였다. 모려 칼슘의 총 함량 범위는 31.8~39.9%이었고, 용출률 변화는 62.7~83.6%이었다 (n=15). ICP-AES 법을 이용한 칼슘 함량 측정을 통해 모려의 품질관리에 적용할 수 있음을 증명하였다.

• Journal of Pharmaceutical Investigation
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• 제19권3호
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• pp.131-136
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• 1989

This study was attempted to investigate the dissolution rate and the bioavailability after oral administration of commercially available aspirin tablets in normal volunteers. The dissolution test was conducted in artificial gastric juice using basket method with three aspirin preparations (A, B and C) which were chemically equivalent. The results were as follows; The dissolution rate was higher in the order of three different brand B>A >C. Area under the blood concentration and peak blood concentration were larger in the order of brand A>B>C. Absorption rate constant and peak time were larger in the order of brand B>A>C, and there was a little difference in elimination rate constant and biological half-life. The correlation of the dissolution rate and absorption rate constant, as well as correlation of the dissolution rate and peak time showed significant linear relationship respectively. From the results of this experiment, it can be concluded that the bioavailability of aspirin tablets showed much difference according to commercial preparations, and that the bioavailability of aspirin tablets in human may be predicted from the results of dissolution rate studies.

• 한국세라믹학회지
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• 제26권6호
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• pp.850-854
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• 1989

The elastic moduli and dissolution rates of 15 glasses with different mole ratios of sodium-magnasium-phosphate as potential non-toxic biomaterials were investigated. In this study, a 3-pint bending test, sonic resonance technique, and theoretical calculation were used to evaluate the modulus of elasticity. The dissolution rates at 37$^{\circ}C$(human body temperature) were determined by the measurement of mass changes in each sample for 24 weeks.

• Journal of Pharmaceutical Investigation
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• 제38권5호
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• pp.335-342
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• 2008

The bioequivalence of two carbamazepine preparations was conducted. The in vivo bioequivalence study in 20 healthy male Korean volunteers was designed by using a single dose, randomized, 2-period crossover with a 3-weeks washout period between the doses. Prior to the in vivo study, an in vitro comparative dissolution test was performed by the paddle and basket method as described in the bioequivalence guidance of the Korea Food and Drug Administration (KFDA). Based on the similar dissolution pattern between two preparations in the dissolution test, the two formulations are demonstrated to be pharmaceutically equivalent. In addition, in vivo bioequivalence test was used to reconfirm the in vitro dissolution results. In the in vivo bioequivalence study, the plasma concentrations of carbamazepine up to 144 h after the administration were determined using a validated HPLC method with UV detection and the bioequivalence between the two drug products was assessed by statistical analysis of the log transformed mean ratios of $C_{max}$, $AUC_{0-t}$ and $AUC_{0-\infty}$. The mean maximum concentration ($C_{max}$) of the test and reference were found to be $1467.0{\pm}335.8\;ng/mL$ and $1465.9{\pm}310.3\;ng/mL$, respectively. The 90% confidence intervals (C.I.) of $C_{max}$ were in the range from 0.95 to 1.05. As for the $AUC_{0-t}$ and $AUC_{0-\infty}$, test values were $110027.1{\pm}27786.4\;ng/mL{\cdpt}h$, $128807.0{\pm}34563.2\;ng/mL{\cdot}h$ and $105473.6{\pm}26496.2\;ng/mL{\cdot}h$, $125448.5{\pm}35975.5\;ng/mL{\cdot}h$, respectively. The 90% C.I. of $AUC_{0-t}$ were 0.97 to 1.10 and of $AUC_{0-\infty}$, 0.99 to 1.09 and thus were within the log 0.8-log 1.25 interval proposed by the KFDA. A two-way ANOVA showed no significant difference between the two formulations. Based on these statistical analysis, it was concluded that the test formulation is bioequivalent to the reference.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.45.1-45.8
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• 2020

Objective: The aim of this study was to introduce a gelatin/bovine serum albumin (BSA) tissue standard, which provides dissolution properties identical to those of biological tissues. Further, the study evaluated whether the utilization of endodontic activating devices led to enhanced phantom dissolution rates. Materials and Methods: Bovine pulp tissue was obtained to determine a benchmark of tissue dissolution. The surface area and mass of samples were held constant while the ratio of gelatin and BSA were varied, ranging from 7.5% to 10% gelatin and 5% BSA. Each sample was placed in an individual test tube that was filled with an appropriate sodium hypochlorite solution for 1, 3, and 5 minutes, and then removed from the solution, blotted dry, and weighed again. The remaining tissue was calculated as the percent of initial tissue to determine the tissue dissolution rate. A radiopaque agent (sodium diatrizoate) and a fluorescent dye (methylene blue) were added to the phantom to allow easy quantification of phantom dissolution in a canal block model when activated using ultrasonic (EndoUltra) or sonic (EndoActivator) energy. Results: The 9% gelatin + 5% BSA phantom showed statistically equivalent dissolution to bovine pulp tissue at all time intervals. Furthermore, the EndoUltra yielded significantly more phantom dissolution in the canal block than the EndoActivator or syringe irrigation. Conclusions: Our phantom is comparable to biological tissue in terms of tissue dissolution and could be utilized for in vitro tests due to its injectability and detectability.