• Journal of Pharmaceutical Investigation
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• 제35권5호
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• pp.355-360
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two cetirizine HCl tablets, Zyrtec tablet (UCB Pharm. Co., Ltd. Korea, reference product) and Zyrix tablet (Kukje Pharm. Co., Ltd., Korea, test product), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (diazepam), plasma samples were extracted using 1 mL of dichloromethane. Compounds extracted were analyzed by reverse-phase HPLC with ultra-violet detector. This method for determination cetirizine is proved accurate and reproducible with a limit of quantitation of 10 ng/mL in male plasma. Twenty-four healthy male Korean volunteers received each medicine at the cetirizine HCl dose of 10 mg in a $2{\times}2$ crossover study. There was a one-week wash out period between the doses. Plasma concentrations of cetirizine were monitored for over a period of 24 hr after the administration. AUC (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals for the log transformed data were acceptable range of log 0.8 to log 1.25 $(e.g.,\;log\;0.93-log\;1.08\;for\;AUC_{0-t},\;log\;0.91-log\;1.08\;for\;AUC_{0-{\infty}}\;and\;log\;1.01-log\;1.11\;for\;C_{max})$. The major parameters, AUC and $C_{max}$ met the criteria of KFDA for bioequivalence indicating that Zyrix tablet is bioequivalent to Zyrtec tablet.

• Journal of Pharmaceutical Investigation
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• 제35권5호
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• pp.383-388
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• 2005

A simple and specific method for determination of methyltestosterone (MT) has been established by a gas chromatography/mass selective detector and applied in plasma of healthy male volunteers received a single oral dose of 50 mg MT $(Testo^{TM}\;tablets,\;25\;mg)$ for bioavailability test. This method involves using liquid-liquid extraction of the sample with diethyl ether and derivatization with MSTFA. MT showed good resolution in this condition. The detection limit of quantitation was 5 ng/ml. A good linearity (r>0.996) was obtained at the range of 5-250 ng/ml of MT. Intra-day precision and accuracy were 2.76-12.56% and 0.39-8.01 %, and inter-day precision and accuracy were 2.29-17.69% and 0.42-7.99%, respectively. The established method was applied on bioavailability test of MT in human volunteers. The value of $AUC_{0\;to\;last}$ to last was $264.5{\pm}123.9\;ng{\cdot}hr/ml$ and that of $AUC_{0\;to\;inf}$ was determined to be $275.2{\pm}126.5\;ng{\cdot}hr/ml$. The values of $C_{max}$ and $T_{max}$ were $95.9{\pm}67.1\;ng/ml$ and $1.13{\pm}0.9\;hr$, respectively. The mean elimination half-life $(t_{1/2})$ was $4.4{\pm}0.9\;hr$. This analytical method is suitable and useful for the pharmacokinetics and bioequivalence studies of MT.

• 대한환경공학회지
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• 제27권6호
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• pp.606-613
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• 2005

본 연구에서는 실내공기 중 포름알데히드를 측정하기 위해 세 가지 다른 반응의 흡광광도법(비색분석)을 응용한 뱃지형 확산측정기를 평가하였다. 흡수여지의 세척방법을 비교한 결과 사용된 세척용액의 종류에 관계없이 세척하지 않은 경우 보다 양호한 세척효과가 나타났다. 각 측정방법에서 사용될 흡수액의 농도는 시료채취율을 기준으로 정하였다. 평가된 공시험 값은 측정방법별로 15% 이내의 편차를 가진 것으로 나타나 대체적으로 안정적인 것으로 나타났다. 확산측정기의 재현성은 MBTH법이 상대표준편차 10% 이내로 가장 양호하며, 채취된 포름알데히드 양과 시간가중평균농도와의 상관관계는 세 가지 측정방법 모두 양호한 것으로 나타났다. 검출한계 및 정량한계는 시료채취율이 가장 좋은 MBTH법이 다른 측정방법과 비교하여 가장 낮게 나타나 시료채취율이 가장 크고 정량한계가 낮은 측정방법일수록 포름알데히드 측정에 요구되는 측정시간이 감소되는 것으로 나타났다.

• Archives of Pharmacal Research
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• 제29권9호
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• pp.777-785
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• 2006

Nelumbinis Semen (NS), or lotus seed, is one of the most well-known traditional herbal medicines and is frequently used to treat cardiovascular symptoms in Korea. The anti-ischemic effects of NS on ischemia-induced isolated rat heart were investigated through analyses of changes in blood pressure, aortic flow, coronary flow, and cardiac output. The subjects in this study were divided into two groups: a control, untreated ischemia-induced group, and an ischemia-induced group treated with NS. There were no significant differences in perfusion pressure, aortic flow, coronary flow and cardiac output between the groups before ischemia was induced. The supply of oxygen and buffer was stopped for ten minutes to induce ischemia in isolated rat hearts, and NS was administered during ischemia induction. NS treatment significantly prevented decreases in perfusion pressure, aortic flow, coronary flow and cardiac output under ischemic conditions (p<0.01). In addition, the mechanism of the anti-ischemic effects of NS was also examined through quantitation of intracellular calcium content in rat neonatal cardiomyocytes. NS significantly prevented intracellular calcium increases induced by isoproterenol (p<0.01). These results suggest that NS has distinct anti-ischemic effects through calcium antagonism.

• 약학회지
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• 제52권1호
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• pp.12-19
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• 2008

The organic acids (formic acid, acetic acid and propionic acid), phenol and benzopyrene in wood vinegar were determine by HPLC. An $Atlantis^{TM}dC_{18}$ column with a acetonitrile: 0.1% phosphoric acid (5: 95, organic acids), acetonitrile: water (10 : 90, phenol), 100% acetonitrile (benzopyrene) as a mobile phase was used. Retention time of acetic acid, formic acid, propionic acid, phenol and benzopyrene was 4.77, 3.73, 9.08, 30.97 and 6.10 min, respectively. The calibration curves of organic acids, phenol, benzopyrene were linear over the concentration range of $30{\sim}500,\;60{\sim}1000$, and $3{\sim}50\;{\mu}g/ml$ with correlation coefficient of above 0.999. The limit of detection (LOD) and limit of quantitation (LOQ) of acetic acid, formic acid, propionic acid, phenol, and benzopyrene was 1.71 and 5.19, 1.11 and 3.35, 4.87 and 14.74, 6.45 and 19.55, 0.08 and $0.24\;{\mu}g/ml$, respectively. The coefficients of variation for intra- and inter-day assay were $0.21{\sim}4.14$ and $0.07{\sim}1.19%$, respectively and the precision was $95{\sim}115%$. From this study, we suggest that HPLC is suitable method for the determination of organics in wood vinegar and could be applied to quality control of wood vinegar.

• Journal of Forest and Environmental Science
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• 제34권1호
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• pp.53-56
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• 2018

Elemental carbon (EC) and organic carbon (OC) mass concentrations in PM2.5 were measured from March through October 2015 in Taehwa Research Forest (TRF). The concentration of carbon in the TRF was $3.4{\mu}g/m^3$ and the concentration of EC was $1.4{\mu}g/m^3$. Also the concentration of $OC_{sec}$ was the highest at $2.84{\mu}g/m^3$ in the summer and the lowest at 1.66 in the spring. The ratio of the secondary generation OC in the total OC was the highest at 62% in the summer. Monthly OC concentration was the lowest at $2.38{\mu}g/m^3$ in April and the highest at $6.60{\mu}g/m^3$ in July. In case of EC concentration was the lowest in April ($0.98{\mu}g/m^3$) and the highest in July ($3.41{\mu}g/m^3$). The OC/EC ratio showed the lowest ratio in March and the highest rate in September. It is suggested that the secondary generation reaction of OC component was active due to sufficient irradiation amount in summer.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3629-3634
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• 2013

In this study, an improved method for the quantitative analysis of ginkgolic acids (GAs) in Ginkgo biloba leaf extract was developed. The samples were extracted with a mixture of chloroform and 50 % ethanol, after which the chloroform extract was dried and reconstituted in methanol. GAs with 13:0, 15:1, and 17:1 in the extract were successfully separated within 40 min and determined with high throughput performance using an online column-switching HPLC method using an SP column C8 SG80 ($4.6{\times}150mm$, $5{\mu}m$) and a Cadenza 5CD C18 column ($4.6{\times}150mm$, $3{\mu}m$). The developed HPLC method was validated for Ginkgo biloba leaf extract. The validation parameters were specificity, linearity, precision, accuracy, and limits of detection and quantitation (LODs and LOQs, respectively). It was found that all of the calibration curves showed good linearity ($r^2$ > 0.9993) within the tested ranges. The LODs and LOQs were all lower than $0.04{\mu}g/mL$. The established method was found to be simple, rapid, and high throughput for the quantitative analysis of GAs in ten commercial Ginkgo biloba leaf extract and dietary supplements. The samples were also analyzed in LC-electrospray ionization (ESI) tandem mass spectrometry (MS/MS) - multiple-ion reaction monitoring (MRM) mode to confirm the identification results that were obtained by the column switching HPLC-DAD method. The developed method is considered to be suitable for the routine quality control and safety assurance of Ginkgo biloba leaf extract.

• 한국환경보건학회지
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• 제29권4호
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• pp.27-34
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• 2003

Bisphenol A is used in the manufacture of epoxy, polycarbonate, and corrosion-resistant unsaturated polyester-styrene resins required for food packaging materials in industrial processing. Some reports indicated the possibility of harmful effects on rats. In this study was used a method for the determination of bisphenol A in blood according to the OSHA High Performance Liquid Chromatography (HPLC) guideline. The method involved blood extraction using methylene chloride. And it was evaluated developmental and teratogenic effects in pregnant rats and second generation. The results obtained were as follows. There was a significant increase in the body weights and treated groups F1 female in liver, spleen, kidney, but according to dose-response. F1 female rat's relative body weight and absolute body weight are not different. There was a significant increase liver, spleen, kidney organ weight and reproductive organ weight epididymis, prostate gland in F1 male rats. There was a proestrous in pregnant rat, group 200 $\mu\textrm{g}$/kg, 2000 $\mu\textrm{g}$/kg, 20,000 $\mu\textrm{g}$/kg. The effect on rat treated with bisphenol A decrease organ weight and reproductive organ weight. Identification and quantitation were performed with using HPLC C18 column and using at retention time 5.5 min. The results of the detection of bisphenol A were at 20,000 $\mu\textrm{g}$/kg in average 1 $\mu\textrm{g}$/ml, 200 $\mu\textrm{g}$/kg average in 0.9 $\mu\textrm{g}$/ml blood samples. From those results, it could be concluded that the effects of pregnant rat and second generation(F1) by bisphenol A treatment during lactational period were estrogenic and bisphenol A was remained in serum at low level.

• Journal of Electrochemical Science and Technology
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• 제7권1호
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• pp.68-75
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• 2016

In this study a new, simple, precise, accurate and economic electrochemical method was developed and validated for the voltammetric determination of zolpidem (ZP) using disposable pencil graphite (PG) electrode. The anodic oxidation of ZP on the surface of the PG electrode was examined in a britton robinson (BR) buffer. Square wave and cyclic voltammetry were used as electrochemical techniques in the potential range of 0-1.2 V in the pH 8 BR buffer. In cyclic voltammetry studies, the diffusion coefficient of ZP oxidation was found to be 3.6×10^-6 cm² s^-1. On the other hand, the ZP has shown a well-defined irreversible anodic peak at 0.98 V in the square wave voltammetry mode. The PG electrode, primarily being graphite which has a large active surface area gives rise to increasing peak current with respect to ZP electrooxidation. PG electrode showed an electrocatalytic effect in anodic oxidation of ZP. A linear relationship between catalytic current response and ZP concentration was obtained over a concentration range of 10-30 μM with R.S.D. values ranging from 0.29-3.89. Limits of detection and quantitation were found to be 1 and 3 μM, respectively. Finally, the PG electrode was successfully used to determine ZP in standard and tablet dosage forms with a mean recovery of 100.69 %.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1956-1964
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• 2014

To provide the scientific corroboration of the traditional uses of Akebia quinata (Thunb.) Decne., a detailed analytical examination of A. quinata stems was carried out using a reversed-phase high performance liquid chromatography (RP-HPLC) method coupled to photodiode array detector (PDA) for the simultaneous determination of four phenolic substances; cuneataside D (1), 2-(3,4-dihydroxyphenyl)ethyl-O-${\beta}$-D-glucopyranoside (2), 3-caffeoylquinic acid (3) and calceolarioside B (4). Particular attention was focused on the main compound, 3-caffeoylquinic acid (3), which has a range of biological functions. In addition, 2-(3,4-dihydroxyphenyl)ethyl-O-${\beta}$-D-glucopyranoside (2) was considered as a discernible marker of A. quinata from its easy confuse plants. The contents of compounds 2 and 3 ranged from 0.72 to 2.68 mg/g and from 1.66 to 5.64 mg/g, respectively. The validation data indicated that this HPLC/PDA assay was used successfully to quantify the four phenolic compounds in A. quinata from different locations using relatively simple conditions and procedures. The pattern-recognition analysis data from 53 samples classified them into two groups, allowing discrimination between A. quinata and comparable herbs. The results suggest that the established HPLC/PDA method is suitable for quantitation and pattern-recognition analyses for a quality evaluation of this medicinal herb.