• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.460-470
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• 2017

Mussels are major fouling organisms causing serious technical and economic problems. In this study, antifouling activity towards mussel was found in three compounds isolated from a marine bacterium associated with the sea anemone Haliplanella sp. This bacterial strain, called PE2, was identified as Vibrio alginolyticus using morphology, biochemical tests, and phylogenetic analysis based on sequences of 16S rRNA and four housekeeping genes (rpoD, gyrB, rctB, and toxR). Three small-molecule compounds (indole, 3-formylindole, and cyclo (Pro-Leu)) were purified from the ethyl acetate extract of V. alginolyticus PE2 using column chromatography techniques. They all significantly inhibited byssal thread production of the green mussel Perna viridis, with $EC_{50}$ values of $24.45{\mu}g/ml$ for indole, $50.07{\mu}g/ml$ for 3-formylindole, and $49.24{\mu}g/ml$ for cyclo (Pro-Leu). Previous research on the antifouling activity of metabolites from marine bacteria towards mussels is scarce. Indole, 3-formylindole and cyclo (Pro-Leu) also exhibited antifouling activity against settlement of the barnacle Balanus albicostatus ($EC_{50}$ values of 8.84, 0.43, and $11.35{\mu}g/ml$, respectively) and the marine bacterium Pseudomonas sp. ($EC_{50}$ values of 42.68, 69.68, and $39.05{\mu}g/ml$, respectively). These results suggested that the three compounds are potentially useful for environmentally friendly mussel control and/or the development of new antifouling additives that are effective against several biofoulers.

• Journal of Pharmaceutical Investigation
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• v.35 no.1
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• pp.39-44
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two cefaclor capsules, Ceclor (Lilly Korea Co., Ltd.) and Kyongbocefaclor (Kyongbo Pharm. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of cefaclor from the two cefaclor formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four healthy male subjects, $22.96{\pm}1.52$ years in age and $67.03{\pm}7.90$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ crossover study was employed. After one capsule containing 250 mg of cefaclor was orally administered, blood was taken at predetermined time intervals and the concentrations of cefaclor in serum were determined using HPLC method with UV detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, 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 reference drug, Ceclor, were -1.90%, 2.68% and -7.60% 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 $(e.g.,\;log0.91{\sim}log\;1.06\;and\;log0.92{\sim}log\;1.18\;for\;AUC_t\;and\;C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kyongbocefaclor capsule was bioequivalent to Ceclor capsule.

• Journal of Pharmaceutical Investigation
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• v.35 no.4
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• pp.309-315
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• 2005

The purpose of the present study was to evaluate the bioequivalence of tamsulosin HCl capsule, $Harnal^{\circledR}$(Jeil Korea Ltd.) and $Yutanal^{\circledR}$(Kukje Korea Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four normal male volunteers, $23.29{\pm}2.14$ year in age and $72.08{\pm}7.83$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one capsule containing 0.2 mg of tamsulosin HCl were orally administered, blood was taken at predetermined time intervals and concentrations of tamsulosin in plasma were determined using LC-MS/MS. Pharmacokinetic parameters such as $AUC_t$, $T_{max}$ and $C_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals for the log transformed data were acceptance range of log0.8 to log1.25 (e.g., $log0.93{\sim}log1.11$ and $log0.80{\sim}log0.94$ for $AUC_t$, and $C_{max}$, respectively). The major parameters, $AUC_t$, and $C_{max}$, met the criteria of KFDA for bioequivalence indicating that $Yutanal^{\circledR}$ capsule is bioequivalent to $Harnal^{\circledR}$ capsule.

• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.437-443
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• 2005

A rapid, selective and sensitive reversed-phase HPLC method for the determination of a major metabolite of terfenadine, fexofenadine, in human serum was developed, validated, and applied to the pharmacokinetic study of terfenadine. Fexofenadine and internal standard, haloperidol were extracted from human serum by liquid-liquid extraction with acetonitrile and analyzed on a $Symmetry^{TM}$ C8 column with the mobile phase of 1% triethylamine phosphate (pH 3.7)-acetonitrile (67:33, v/v, adjusted to pH 5.6 with triethylamine). Detection wavelength of 230 nm for excitation, 280 nm for emission and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed fexofenadine concentration (50 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 10-500 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 10 ng/mL, which was sensitive enough for the pharmacokinetic studies of terfenadine. The overall accuracy of the quality control samples ranged from 95.70 to 114.58% for fexofenadine with overall precision (% C.V.) being 3.53-14.39%. The relative mean recovery of fexofenadine for human serum was 90.17%. Stability studies (freeze-thaw, short-term, extracted serum sample and stock solution) showed that fexofenadine was stable during storage, or during the assay procedure in human serum. However, the storage at $-70^{\circ}C$ for 4 weeks showed that fexofenadine was not stable. The peak area and retention time of fexofenadine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of fexofenadine in human serum samples for the pharmacokinetic studies of orally administered Tafedine tablet (60 mg as terfenadine) at three different laboratories, demonstrating the suitability of the method.

• Journal of Pharmaceutical Investigation
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• v.32 no.3
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• pp.223-229
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• 2002

Metformin is an oral antihyperglycemic agent used in the therapy of noninsulin-dependent diabetes mellitus and does not cause hypoglycemia at the therapeutic dose. Its mechanism of action may involve an increased binding of insulin to its receptors and glucose uptake at the post-receptor level. The purpose of the present study was to evaluate the bioequivalence of two metformin tablets, Glucophage (Daewoong Pharmaceutical Co., Ltd.) and Glycomin (Ilsung Pharmaceuticals Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The metformin release from the two metformin tablets in vitro was tested using KP VII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four normal male volunteers, $23.75{\pm}1.96$ years in age and $68.77{\pm}10.41\;kg$ in body weight, were divided into two groups with a randomized $2{\times}2$ cross-over study. After one tablet containing 500 mg as metformin was orally administered, blood was taken at predetermined time intervals and the concentrations of metformin in serum were determined using HPLC with UV detector. Besides, the dissolution profiles of two metformin tablets were very similar at 떠1 dissolution media. The pharmacokinetic parameters such as $AVC_t,\;C_{max}\;and\;T_{max}$ were calculated. The ANOVA test was performed for the statistical analysis of the logarithmically transformed $AVC_t\;and\;C_{max}$, untransformed $T_{max}$. The results showed that the differences in $AVC_t,\;C_{max}\;and\;T_{max}$ between two tablets based on the Glucophage were 0.09%, 6.09% and -8.22%, 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) $(e.g.,\;log(0.94){\sim}log(1.09)\;and \;log(1.01){\sim}log(1.15)$\;for\;AVC_t\;and\;C_{max},\;respectively)$, indicating that Glycomin tablet is bioequivalent to Glucophage tablet.

• Journal of Pharmaceutical Investigation
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• v.34 no.5
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• pp.419-425
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• 2004

The purpose of the present study was to evaluate the bioequivalence of two propiverine hydrochloride tablets, BUP-4 (Jeil Pharm. Co., Ltd.) and Kuhnil Propiverine Hydrochloride (Kuhnil Pharm. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The propiverine release from the two propiverine hydrochloride 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 solutions, water and blend of polysorbate 80 into pH 6.8). Twenty six healthy male subjects, $23.73{\pm}2.79$ years in age and $67.04{\pm}7.93\;kg$ in body weight, were divided into two groups and a randomized $2\;{\times}\;2$ cross-over study was employed. After one tablet containing 20 mg as propiverine hydrochloride was orally administered, blood was taken at predetermined time intervals and the concentrations of propiverine 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 BUP-4 were 0.17%, 7.98% and 4.55% 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) $(e.g.,\;log(0.88){\sim}log(1.l2)\;and\;log(0.90){\sim}log(1.l5)\;for\;AUC_t\;and\;C_{max},\;respectively)$. Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kuhnil Propiverine Hydrochloride tablet was bioequivalent to BUP-4 tablet.

• Journal of Pharmaceutical Investigation
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• v.32 no.3
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• pp.215-221
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• 2002

Cephradine is a first generation cephalosporin and has broad spectrum antibacterial activity against gram-positive and gram-negative microorganisms, through inhibition of bacterial cell wall synthesis. Cephradine is useful for treatment of infections of the urinary and respiratory tract, skin and soft tissues. The purpose of the present study was to evaluate the bioequivalence of two cephradine capsules, Cefradine Yuhan (YuHan Corporation) and Broadcef (Ilsung Pharmaceuticals Co. Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The cephradine release from the two cephradine capsules in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty normal male volunteers, $23.10{\pm}2.90$ years in age and $67.69{\pm}8.04\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one capsule containing 500 mg as cephradine was orally administered, blood was taken at predetermined time intervals and the concentrations of cephradine in serum were determined using HPLC method with UV detector. The dissolution profiles of two cephradine capsules were very similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AVC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AVC_t\;and\;C_{max}$ and untransformed $T_{max}$. The results showed that the differences in $AVC_t,\;C_{max}\;and\;T_{max}$ between two capsules based on the Cefradine Yuhan were -2.87%, -0.96% and -4.85%, respectively. There were no sequence effects between two capsules in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of 1og(0.8) to log(1.25) $(e.g.,\;log(0.93){\sim}log(1.02)\;and\;log(0.88){\sim}log(1.13)\;for \;AVC_t\;and\;C_{max},\;respectively)$. The 90% confidence interval using untransformed data was within ${\pm}20%$ $(e.g., \;-17.54{\sim}7.78\;for\;T_{max})$. All parameters met the criteria of KFDA guideline for bioequivalence, indicating that Broadcef capsule is bioequivalent to Cefradine Yuhan capsule.

• Journal of Pharmaceutical Investigation
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• v.35 no.4
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• pp.265-271
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• 2005

A rapid, selective and sensitive reversed-phase HPLC method for the determination of etodolac in human serum was developed, validated, and applied to the pharmacokinetic study of etodolac. Etodolac and internal standard, ibuprofen were extracted from human serum by liquid-liquid extraction with hexane/isopropanol (95:5, v/v) and analyzed on a Luna C18(2) column with the mobile phase of 1% aqueous acetic acid-acetonitrile (4:6, v/v). Detection wavelength of 227 nm and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^3$ factorial design using a fixed etodolac concentration $(1\;{\mu}g/mL)$ with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of $0.05-40\;{\mu}g/mL$ with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 0.05 ${\mu}g/mL$, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 92.00 to 110.00% for etodolac with overall precision (% C.V.) being 1.08-10.11%. The percent recovery for human serum was in the range of 76.73-115.30%. Stability studies showed that etodolac was stable during storage, or during the assay procedure in human serum. The peak area and retention time of etodolac were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of etodolac in human serum samples for the pharmacokinetic studies of orally administered Lodin XL tablet (400 mg as etodolac) at three different laboratories, demonstrating the suitability of the method.

• Journal of Pharmaceutical Investigation
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• v.35 no.6
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• pp.423-429
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• 2005

A selective and sensitive reversed-phase HPLC method for the determination of fenoprofen in human serum was developed, validated, and applied to the pharmacokinetic study of fenoprofen calcium. Fenoprofen and internal standard, ketoprofen, were extracted from human serum by liquid-liquid extraction with diethyl ether and analyzed on a Luna C18(2) column with the mobile phase of acetonitrile-3 mM potassium dihydrogen phosphate (32:68, v/v, adjusted to pH 6.6 with phosphoric acid). Detection wavelength of 272 nm and flow rate of 0.25 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed fenoprofen concentration $(2\;{\mu}g/mL)$ with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of $0.05-100\;{\mu}g/mL$ with correlation coefficients greater than 0.999. The lower limit of quantification using 1 mL of serum was $0.05\;{\mu}g/mL$, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 92.27 to 109.20% for fenoprofen with overall precision (% C.V.) being 5.51-11.71 %. The relative mean recovery of fenoprofen for human serum was 81.7%. Stability (freeze-thaw, short and long-term) studies showed that fenoprofen was not stable during storage. But, extracted serum sample and stock solution were allowed to stand at ambient temperature for 12 hr prior to injection without affecting the quantification. The peak area and retention time of fenoprofen were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of fenoprofen in human serum samples for the pharmacokinetic studies of orally administered Fenopron tablet (600 mg as fenoprofen) at three different laboratories, demonstrating the suitability of the method.

• Analytical Science and Technology
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• v.28 no.5
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• pp.309-316
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• 2015

The analytical method of lead in plasma by ICP-MS was validated after securing environment within class 1,000 classification. We tested specificity and accuracy of within-run and between-run. According to measurement of the amount of suspended particulates in a clean room, 0.3~62 particles were detected in 0.3 µm size while 0.0~28.3 particles were observed in 0.5 µm size. Total suspended particulates met required environment with up to 90.3 particles. The MDL (Method detection limit) of the sample which has been fabricated using fetal bovine serum (FBS) blank was 1.77 ng/L, and LOQ (Limit of quantification) was 5.55 ng/L. The slope, intercept and correlation coefficient of the calibration curve were y=1.09×10⁻³x+4.88×10⁻² and r=0.9999, which showed good correlation. The specificity, within-run and between-run accuracy satisfied the standard at more than 50 ng/L. The average lead concentration in plasma of the general people, current workers and retired workers was 55.4 ng/L, 440 ng/L, and 132 ng/L.