• Journal of Electrochemical Science and Technology
• /
• v.5 no.4
• /
• pp.115-127
• /
• 2014

Cd-Pb thin films were electrodeposited from a diluted chloride solution using stainless steel rotating disc electrode. The linear sweep voltammograms of the single metallic ions show that electrodeposition of these ions was mass transfer control due to the plateau observed for different rotations at concentration (50 and 200 ppm). The voltammograms of binary system elucidate that electrodeposition process always start at cathodic potential located between the potential of individual metals. Currents transients measurements, anodic linear sweep voltammetry (ALSV) and atomic force microscopy (AFM) were used to characterize the electrocryatalization process and morphology of thin films. ALSV profiles show a differentiation for the dissolution process of individual metals and binary system. Two peaks of dissolution Cd-Pb film were observed for the binary system with different metal ion concentration ratios. The model of Scharifker and Hills was used to analyze the current transients and it revealed that Cd-Pb electrocrystalization processes at low concentration is governed by three-dimensional progressive nucleation controlled by diffusion, while at higher concentration starts as a progressive nucleation then switch to instantaneous nucleation process. AFM images reveal that Cd-Pb film electrodeposited at low concentration is more roughness than Cd-Pb film electrodeposited at high concentrated solution.

• YAKHAK HOEJI
• /
• v.48 no.5
• /
• pp.297-302
• /
• 2004

The purpose of the present study was to evaluate the bioequivalence of two cimetidine tablets, Tagamet (Yuhan Pharm. Co., Ltd.) and Nex (Bi-nex Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The cimetidine release from the two cimetidine tablets in vitro was tested using KP Apparatus I method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solutions and water). The dissolution profiles of two cimetidine tablets were very similar at all dissolution media. Twenty four healthy male volunteers were divided into two groups with a randomized $2{\times}2$ cross-over study. After four tablets (800 mg cimetidine) were orally administrated, blood was taken and the concentrations of cimetidine in serum were determined using HPLC with UV detector. The pharmacokinetic parameters such as $AUC_{t}$, $C_{max}$ and $T_{max}$ were determined. The result showed that the differences in $AUC_{t}$, and $C_{max}$ between two cimetidine tablets based on the Tagamet were -6.82% and -12.98%, respectively. There were no sequence effects between two tablets in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., log(0.90)log(0.97) and log(0.82)log(0.93) for $AUC_{t}$ and $C_{max}$, respectively), indicating that Thrumetin tablet was bioequivalent to Tagamet tablet.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.311.2-312
• /
• 2003

The purposes of this study were to evaluate bioequivalence (BE) using In-transformed pharmacokinetic parameters obtained from two fluconazole products and to develop the analytical methods for the quantitative determination of fluconazole in human serum. In addition, the in vitro dissolution profiles of the two fluconazole products at dissolution media: 0.1 M hydrochloride (KP Ⅶ Apparatus II method) were assessed. (omitted)

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.420.1-420.1
• /
• 2002

The purposes of this study were to evaluate bioequivalence (BE) using In-transformed pharmacokinetic parameters obtained from two tiropramide HCI products and to develop the analytical methods for the quantitative determination of tiropramide in human serum. In addition. the in vitro dissolution profiles of the two tiropramide HCI products in various dissolution media: pH 1.2, 4.0. 6.8 and water (KP Ⅶ Apparatus II method) were assessed. BE was evaluated in 20 healthy male Korean volunteers in randomized crossover study. (omitted)

• Journal of Pharmaceutical Investigation
• /
• v.40 no.1
• /
• pp.9-14
• /
• 2010

Lacidipine used for the treatment of hypertension has low water solubility and is classified as BCS Class II category. Gelucire-based solid dispersions (SD) containing lacidipine were prepared by solvent evaporation method to enhance drug dissolution. The powdered forms of SD showed irregularly spherical shape. Thermal behaviors of SD from differential scanning calorimetry indicated that distinct endothermic peak of lacidipine ($184^{\circ}C$) was shifted to lower region ($150.1^{\circ}C$). Drug was present in a crystalline form. NMR spectra also showed some molecular interaction between drug and Gelucire. There was no significant difference in DSC and NMR behaviors between Gelucire 44/14 and Gelucire 50/13. The initial dissolution rate of SD-loaded tablet linearly increased both in water and in water containing 1% tween 20, and much higher than the commercial tablet, $Vaxar^{(R)}$. When the amount of SD was increased, the release rate was greater. The Gelucire 50/13 showed higher dissolution than the Gelucire 44/14. The produced solid dispersion with various kinds of excipients and making tablets, it was found that solid dispersions can increase the solubility in artificial gastric juice and finally increases dissolution rate.

• Journal of Pharmaceutical Investigation
• /
• v.39 no.6
• /
• pp.417-422
• /
• 2009

Budesonide belongs to Class II in the Biopharmaceutics Classification System (BCS) for its high permeability and poor aqueous solubility. The purpose of this study was to improve the solubility and dissolution rate of budesonide using an o/w microemulsion system in order to develop a nasal formulation. Based on the results of the solubility study and pseudo ternary phase diagrams, microemulsions of about 80 nm in mean diameter were formulated using isopropyl myristate and Labrasol$^{(R)}$ as an oil phase and a surfactant, respectively. Solubility of budesonide in the microemulsions increased up to 6.50 mg/mL, which is high enough for a nasal formulation. In vitro release profiles of budesonide significantly increased from the microemulsions compared to that of the budesonide powder. These results suggest that the microemulsions of budesonide could further be developed into a clinically useful nasal formulation.

• Journal of Pharmaceutical Investigation
• /
• v.39 no.3
• /
• pp.221-226
• /
• 2009

The purpose of the present study was to evaluate the bioequivalence of two alprazolam tablets, Xanax 0.25 mg (Pharmacia Korea Pharm. Co., Ltd.) and Zyren 0.25 mg (Kwang Dong Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The alprazolam release from two alprazolam tablets in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solutions and water). The dissolution profiles of two alprazolam tablets were very similar at all dissolution media. Twenty four healthy male volunteers were divided into two groups with a randomized 2${\times}$2 cross-over study. After four tablets (1 mg alprazolam) were orally administrated, blood was taken and the concentrations of alprazolam in serum were determined using LC/MS/MS. The pharmacokinetic parameters such as $AUC_t$, $C_max$ and $T_max$were determined. Our results showed that the differences in $AUC_t$, $C_max$ and $T_max$ between two alprazolam tablets based on the Xanax were -11.65%, -4.44% and -39.31%, respectively. There were no sequence effects between two tablets in these parameter. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25)(e.g., log(0.8386)${\sim}$log(0.9453) and log(0.8596)${\sim}$log(1.1040) for $AUC_t$, $C_max$, respectively). Thus, Zyren 0.25 mg tablet was bioequivalent to Xanax 0.25 mg tablet.

• Journal of Pharmaceutical Investigation
• /
• v.40 no.1
• /
• pp.15-21
• /
• 2010

Sibutramine is an orally administered centrally-acting antiobesity agent and inhibits both noradrenaline(norephinephirine) and serotonin(5-HT) reuptake. These effects are contributed by its active metabolites, M1 and M2. However, as the free base form of sibutramine is an oil form in room temperature, it had the problem of handling and stability. Thus, this drug should be used in the form of acid salt form in the pharmaceutical application. Unfortunately, anhydrous sibutramine hydrochloride is highly hygroscopic and unstable. In order to solve the hygroscopicity of the anhydrous salt form, another sibutramine acid salt form must be developed as a hydrate form. In this study. to overcome these problems, various of sibutramine acid salt forms were prepared with the pharmaceutically available salts such as maleate, esylate, mandelate, camsylate, besylate, salicylate, tartrate, isethionate and malate forms, and their physicochemical properties were investigated. Sibutramine malate was selected for excellent solubility and stability among the listed salt forms above. Its pharmacokinetic parameters were evaluated in rats comparing with sibutramine HCl, resulting in similar parameters. In vitro dissolution study of sibutramine malate-loaded capsule was performed comparison with commercial product ($Reductil^{(R)}$) in pH 1.2, pH 4.0, pH 6.8 and water medium. Our results indicated that there were no significant differences in their dissolution profiles were similar in all tested medium. Thus, sibutramine malate-loaded capsule should be a potential candiate due to its excellent solubility, good stability and biosimilar absorption.

• Economic and Environmental Geology
• /
• v.45 no.2
• /
• pp.89-104
• /
• 2012

The solubility of aluminum for two Andisol profiles formed on pyroclastic materials and basaltic rocks from Jeju Island, Korea was investigated. It is found that high organic carbon content and $Al_{pyrophosphate}/Al_{oxalate}$ ratios in the A horizons, suggesting the substantial amounts of reactive Al are associated with organic matter, whereas the low organic carbon content and the $Al_{pyrophosphate}/Al_{oxalate}$ ratios in the Bo horizons indicate that a major part of the reactive Al should be bound inorganically. The differential FT-IR spectra following acid-oxalate dissolution and heating up to 150 and $350^{\circ}C$, and transmission electron microscope (TEM) observation confirm that imogolite is in the Bo horizon. Our results of equilibration experiments demonstrate that the Al solubility in the Bo horizon for Andisols can be clarified by the congruent dissolution model for imogolite-type material (ITM), rather than by the simultaneous equilibrium with both ITM and Al hydroxy-interlayered aluminosilicate. With results from dialysis and aging procedures, it is noted that the formation of a proto imogolite sol showing its transformation to imogolite, which supports the congruent dissolution of ITM primarily controlling the Al solubility of Andisols in Jeju Island, Korea.

• Journal of Pharmaceutical Investigation
• /
• v.34 no.2
• /
• pp.147-153
• /
• 2004

The purpose of the present study was to evaluate the bioequivalence of two glimepiride tablets, $Amaryl^{\circledR}$ (Handok/Aventis Pharm. Co., Ltd.) and Glimed (Kuhn II Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The glimepiride release from the two glimepiride formulations in vitro was tested using KP VIII Apparatus II method with a variety of dissolution media (pH 1.2, 4.0, 6.8 buffer solution, water and blend of PSB 80 into each dissolution medium). Twenty six healthy male subjects, $22.65{\pm}2.19$ years in age and $66.55{\pm}8.85$ kg in body weight, were divided into two groups and a randomized $2\;{\times}\;2$ cross-over study was employed. After one tablet containing 2 mg as glimepiride was orally administered, blood was taken at predetermined time intervals and the concentrations of glimepiride in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the Amaryl were -3.70, -8.28 and 0.61% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., $log(0.84){\sim}log(1.04)$ for $log(0.82){\sim}log(1.03)$ for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA guideline for the bioequivalence were satisfied, indicating Glimed tablet and Amaryl tablet were bioequivalent.