• Journal of Pharmaceutical Investigation
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• v.14 no.3
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• pp.122-130
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• 1984

The dissolution profiles of the seven branded prednisolone tablets were determined by means of available compendium. Those tablets were stored at $40^{\circ}C,\;50^{\circ}C\;and\;60^{\circ}C$ for 15, 30 and 60 days respectively. Under the stress conditions, the dissolution efficiency showed significant changes. It is considered that the determination of shelf life of drug from these aging effects is possible because the dissolution data followed a logarithmic distribution. There were no substantial differences of dissolution between two prednisolone formulations with different particle size not larger than $100\;{\mu}m$. The effect of two starches (corn and potato) on the rate of dissolution of prednisolone from dosage form was also investigated. All marketed tablets met the requirement of the established compendium.

• Corrosion Science and Technology
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• v.14 no.6
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• pp.273-279
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• 2015

Effects of passive film quality by chemical passivation and solution flow on the corrosion behavior of 304 stainless steel in HCl solution were investigated using a coloration indicator, and by corrosion weight loss, electrochemical polarization and element dissolution measurements. A high redness degree suggests a low passive-film integrity for 304 stainless steel following air exposure, while the minimum redness degree for the samples after chemical passivation suggests a high passive-film integrity. In the static condition, samples subjected to air exposure exhibited a high corrosion rate and preferential dissolution of Fe. Chemical passivation inhibited the corrosion rate due to the intrinsically high structural integrity of the passive film and high concentrations of Cr-rich oxides and hydroxide. Solution flow accelerated corrosion by promoting both the anodic dissolution reaction and the cathodic reaction. Solution flow also altered the preferential dissolution to fast uniform dissolution of metal elements.

• Korean Journal of Clinical Pharmacy
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• v.6 no.2
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• pp.14-18
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• 1996

This study was attempted to investigate the dissolution rate and the bioavailability after oral administration of commercially available norfloxacin tablets in rabbits. The dissolution test was conducted in artificial gastric juice using basket method with for norfloxacin preparations (A, B, C and D) which were chemically equivalent. The results were as follows ; The dissolution rate was increased in the order of four different brand A>D>B>C. Area under the plasma concentration curve and peak plasma concentration were increased in the order of brand A>D>B>C. Absorption rate constant and peak time were increased in the order of brand B>A>C>D, and there was a little difference in elimination rate constant and biological half-life. The correlation of the dissolution rate and relative bioavailability showed significant linear relationship. From the results of this experiment, the bioavailability of norfloxacin tablets in rabbits may be predicted from the results of dissolution rate studies.

• Journal of Pharmaceutical Investigation
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• v.13 no.3
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• pp.104-109
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• 1983

The effect of diluents on the dissolution rate of indomethacin was studied and the dissolution rate for the marketed products was compared to establish the quality standard for indomethacin preparation. The results are as fellows 1. The effect of test methods was not significant in the case of paddle method but was greatly effected in the case of basket method. 2. The effect of diluents was not significant generally, but in the case of starch dissolution rate was greatly effected. 3. The dissolution rate was remarkably decreased in proprotion to increase of capsule size. 4. The marketed products met the KP dissolution requirement but showed a little difference due to manufacturers.

• Journal of Pharmaceutical Investigation
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• v.28 no.2
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• pp.81-85
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• 1998

Three polymorphic modifications and two pseudopolymorphic modifications of cefotaxime sodium were obtained by crystallization from different organic solvents. The isolated crystal forms were characterized by UV spectrophotometry, DSC, TGA and X-ray crystallography. Crystal forms of cefotaxime sodium were also compared by dissolution rate. The dissolution rate of form 1 was the highest, followed by form 2, form 4, form 6, form 5 and form 3. Among these polymorphic modifications the dissolution rate of form 3 and form 5 was much slower than that of cefotaxime sodium on the market. All forms showed no change after 2-month storage test in the silica gel desiccator. But after the storage of 2-month at 95% relative humidity condition, all forms were deliquesced by hygroscopic property except form 1 that showed the highest dissolution rate. At 52% relative humidity condition, form 1, form 2 and form 6 had no evidence of phase transformation, but form 3, form 4 and form 5 were also deliquesced.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.3
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• pp.366-378
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• 2009

The purpose of this study was to understand fashion product consumers' relationship dissolution by considering the characteristics of customer behavior and examining the connection between the main variables. The survey was conducted on 623 women over 20 years old who had experienced relationship dissolution or problems with regular fashion stores in the areas of Seoul and Kyungki in September 2005. The SPSS 12.0 package and Amos program were used to analyze the data. The results of this study were as follows: First, service recovery justice of a fashion store, interactional justice, distributive justice, and procedural justice had effects on encounter satisfaction. Furthermore, encounter satisfaction influenced relationship dissolution behavior, voice, exit, loyalty, neglect via overall satisfaction. Second, there were differences in relationship dissolution behavior according to consumer loyalty and switching costs.

• Journal of Pharmaceutical Investigation
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• v.20 no.3
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• pp.121-127
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• 1990

Mefenamic acid has been widely used clinically as an anti-inflammatory analgesic. It has poor solubility in water $(41\;{\mu}g/ml)$ and there is the difficulty of dissolution in the mefenamic acid capsules. A study was made to investigate the effect of various surfactants on the dissolution of mefenamic acid capsules. The surfactants used were sodium lauryl sulfate (SLS), Pluronic F-68, F-77, and F-127. Mefenamic acid capsule containing surfactant showed significantly improved dissolution characteristics. The dissolution rate was fast in the order of SLS > F-77 > F-68 > F-127 in mefenamic acid capsules containing 0.2 w/w % surfactant. SLS was selected for further study on the bioavailability in rabbits. The area under the plasma concentration-time curve $(AUC_{0-24})$ of mefenamic acid capsule containing SLS was higher than one of mefenamic acid capsule not containing surfactant.

• Journal of Pharmaceutical Investigation
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• v.19 no.2
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• pp.63-69
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• 1989

Dissolution characteristics of indomethacin (IMC) from hydrophobic polymer solid dispersions were investigated. IMC-polyvinyl chloride (PVC) and IMC-ethylcellulose (EC) solid dispersions were prepared. The dissolution patterns of pure IMC, IMC-PVC and IMC-EC solid dispersions prepared at various ratios (1:1, 1:3, 1:5, 1:9 and 1:19 w/w), and those of corresponding physical mixtures were compared. It was found that the dissolution rates of IMC from solid dispersions with PVC or EC decreased in the order of 1:1>1:3>1:5>1:9>1:19 as the drug to polymer ratios decreased. Also the dissolution rates of IMC from EC solid dispersions increased according to flow rate, but PVC solid dispersions were not affected significantly. After all, PVC and EC matrices could be applied in sustained-release preparation of IMC.

• Journal of Pharmaceutical Investigation
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• v.40 no.6
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• pp.339-345
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• 2010

Fenofibrate has been used for many years to lower cholesterol levels and its pharmacokinetic profile is well understood. However, due to its low solubility in water, it has low bioavailability after oral administration. In order to improve the dissolution rate, fenofibrate was formulated into a self-microemulsifying drug delivery systems (SMEDDS). We used pseudo-ternary phase diagrams to evaluate the area of microemulsification, and an in vitro dissolution test was used to investigate the dissolution rate of fenofibrate. The optimized formulation for in vitro dissolution assessment consisted of Lauroglycol FCC (60%), Solutol HS 15 (27%), and Transcutol-P (13%). The mean droplet size of the oil phase in the microemulsion formed from the SMEDDS was about 130 nm. The dissolution rate of fenofibrate from SMEDDS was significantly higher than that of the reference tablet. Our studies suggested that the fenofibrate containing SMEDDS composition can effectively increase the solubility and oral bioavailability of poorly water-soluble drugs.

• YAKHAK HOEJI
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• v.31 no.5
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• pp.286-295
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• 1987

The relationship between in vitro release and in vivo bioavailability of acetaminophen from suppositories was investigated. Effect of glycyrrhizin on the drug release and rectal absorption in rats was also examined. Suppositories containing 25mg of acetaminophen were prepared with Wecobee FS (fatty base) or PEG (water-soluble base) bases. The release from the suppositories were determined with USP rotating basket dissolution apparatus and with the suppository release tester. The temperature of the dissolution medium was very critical for the dissolution of acetaminophen from Wecobee FS suppositories. The bioavailability of acetaminophen was calculated from the plasma concentration-time curve after rectal administration of the suppositories to the rats. There were no significant differences in AUC following rectal administration of Wecobee FS and PEG suppositories, but the release and absorption from the Wecobee FS suppositories were faster than those from PEG suppositories. The dissolution rate obtained by the suppository release tester was better correlated with in vivo absorption rate constant than that by the USP dissolution apparatus. It suggests that the partitioning between rectal fluid and suppository base is the rate-limiting step in the rectal absorption of acetaminophen from suppositories. Glycyrrhizin was found not to affect in vitro dissolution and rectal absorption of acetaminophen.