• Proceedings of the Korean DIstribution Association Conference
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• 2005.05a
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• pp.87-110
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• 2005

So far, the studies on the dissolution of relationship have regarded dissolution intention as the final consequence, therefore have not investigated phenomena after the formation of dissolution intention. This study is a seminal work which shows the mechanisms of deterioration of dissolution intention toward complete dissolution. So, this study has the scope from the formation of dissolution intention and to the right before of the complete dissolution. This study has investigated the consequences of dissolution intention(increasing opportunism, decreasing transaction specific investment, and decreasing cooperation) and the relationships of them empirically. As the result of hypotheses test using data collected from 179 newspaper branch office samples, all hypotheses are supported. Dissolution intention has the positive effect on opportunism and negative effect on transaction specific investment. Opportunism decrease transaction specific investment and cooperation. And, transaction specific investment has the positive effect on cooperation. Finally, the authors discussed the theoretical contributions, managerial implications, and limitations of this study and presented the future research directions.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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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.

• Korean Journal of Clinical Pharmacy
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• v.1 no.1
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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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• v.23 no.1
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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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• v.19 no.1
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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.

• Analytical Science and Technology
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• v.23 no.4
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• pp.389-394
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• 2010

An ICP-AES method for determination of calcium content and dissolution characteristics of oyster shell (Ostrea gigas) has been developed and validated. Total calcium content in oyster shell was determined using ICPAES. The dissolution characteristics, which would reflect the composition of $CaCO_3$ polymorphs and calcium salts in oyster shell, were also evaluated by dissolution test. The total calcium contents ranged from 31.8 to 39.9% and the dissolution ratios varied from 62.7 to 83.6% (n=15). The determination of calcium content and dissolution characteristics by ICP-AES would provide useful information for the quality control of oyster shell.

• Journal of Pharmaceutical Investigation
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• v.19 no.3
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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.

• Journal of the Korean Ceramic Society
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• v.26 no.6
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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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• v.38 no.5
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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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• v.45 no.4
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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.