• 분석과학
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• 제33권2호
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• pp.59-67
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• 2020

Nadolol is a β-blocker drug, which effectively manages hypertension and angina pectoris. Its chemical structure allows the formation of four possible stereoisomers. A coupled column high-performance liquid chromatographic (HPLC) system with UV and fluorescence detection was investigated for simultaneously determining four nadolol enantiomers in human plasma. The plasma samples were prepared using a convenient liquid-liquid extraction process and passed through HPLC. Nadolol was initially separated from the endogenous compounds or other impurities in human plasma on a Phenomenex silica column, and its enantiomers were resolved and determined on a Chirapak AD-H column. The developed HPLC method achieved an effective chiral separation and significantly eliminated endogenous compound interference. This optimal HPLC method was validated following FDA guidelines. The results showed good selectivity, linearity, accuracy (90.50 % - 105.27 %), and precision (RSDs < 9.52 %) for each enantiomer. This method was also successfully applied to determine nadolol enantiomers in the plasma samples of a healthy male volunteer (after orally administering 80 mg racemic nadolol), proving its suitability for nadolol stereoselective pharmacokinetic studies.

• Archives of Pharmacal Research
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• 제28권4호
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• pp.463-468
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• 2005

The purpose of the present study was to develop a standard protocol for imidapril hydrochloride bioequivalence testing. For this reason, a specific LC-MS method was developed and validated for the determination of imidapril in human plasma. A solid-phase extraction cartridge, $Sep-pak^{R}$ C18, was used to extract imidapril and ramipril (an internal standard) from deproteinized plasma. The compounds were separated using a XTerra $MS^{R}$?C18 column ($3.5 {\mu}m, 2.1\times150 mm$) and $acetonitrile-0.1\%$ formic acid (67:33, v/v) adjusted to pH 2.4 by 2 mmol/L ammonium formic acid, as mobile phase at 0.3 mL/min. Imidapril was detected as m/z 406 at a retention time of ca. 2.3 min, and ramipril as m/z 417 at ca. 3.6 min. The described method showed acceptable specificity, linearity from 0.5 to 100 ng/mL, precision (expressed as a relative standard deviation of less than $15\%$), accuracy, and stability. The plasma concentration-versus-time curves of eight healthy male volunteers administered a single dose of imidapril (10 mg), gave an $AUC_{12hr}$ of imidapril of $121.48\pm35.81 ng mL^{-1} h$, and $C_{max} and T_{max}$ values of $32.59\pm9.76 ng/mL and 1.75\pm0.27 h$. The developed method should be useful for the determination of imidapril in plasma with sufficient sensitivity and specificity in bioequivalence study.

• Archives of Pharmacal Research
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• 제29권4호
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• pp.339-342
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• 2006

A simple high performance liquid chromatographic (HPLC) method was developed for the determination of tolperisone in human plasma. Tolperisone and internal standard (chlorphenesin) were isolated from 1 mL of plasma using 8 mL of dichlormethane. The organic phase was collected and evaporated under nitrogen gas. The residue was then reconstituted with 300 mL aliquot of mobile phase and a 100 mL aliquot was injected onto the $C_{18}$ reverse-phased column. The mobile phase, $45\%$ methanol containing $1\%$ glacial acetic acid and $0.05\%$ 1-hexanesulfonic acid was run at a flow rate of 1 mL/min. The column effluent was monitored using UV detector at 260 nm. The retention times for tolperisone and the internal standard were approximately 7.1 and 8.4 min, respectively. The standard curve was linear with minimal intra-day and inter-day variability. The quantification limit of tolperisone in human plasma was 10 ng/ mL. The proposed method has been applied to the determination of pharmacokinetic profile of tolperisone in Koreans. The T max of tolperisone in Koreans $(0.94{\pm}0.42\;h)$ was not significantly differ from that reported in Europeans (0.5-1 h), but the mean half-life in Koreans $(1.14{\pm}0.27\;h)$ was shorter than that in Europeans $(2.56{\pm}0.2\;h)$. The proposed HPLC method is simple, accurate, reproducible and suitable for pharmacokinetic study of tolperisone.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.119.1-119.1
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• 2014

Toxic waste disposal: Many people think that when toxic waste is dumped into the ocean or into the air, it disappears. This belief is incorrect. Rather than disappearing, it accumulates over time and slowly destroys the environment. Ultimately, it leads to the destruction of human race. Plasma is environmentally friendly: Plasma is environmentally friendly because it is created and disappears. When plasma is formed on the earth, you need certain conditions such as accelerating electrons by an electrical discharge or a particle accelerator. When this is gone, plasma completely disappears, leaving no impact on the environment. Plasmas produce radicals: Even if plasma density is low at atmospheric pressure, many radicals (excited states of molecules) are created. These radicals are chemically very aggressive. So instead of using harmful chemicals, plasma can be utilized for less of an impact on the environment. Plasma can reach very high temperatures: Plasma is also useful because when you control the density, you can easily reach high temperatures up to $5000{\sim}6000^{\circ}C$ at atmosphere pressure. Because of this heat and the chemical aggressiveness of the plasma, there are many green applications for plasma technology. Pulsed power technology: Pulsed electric field for extraction, drying and killing bacteria. Treatment of biological tissue by pulsed electric fields: Extraction of substances from cells: Sterilisation, Medical applications, Growth stimulation, Food preparation. Each application has its specialities, especially with respect to pulse shape and electric field strength.

• Journal of Pharmaceutical Investigation
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• 제39권1호
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• pp.73-78
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• 2009

A simple LC-MS/MS method of rabeprazole in human plasma was developed and validated. Rabeprazole and Internal standard (I.S), omeprazole, were extracted from human plasma by liquid liquid extraction, chromatographic separation of rabaprazole in plasma was achieved at $45^{\circ}C$ with a Shiseido UG120 $C_{18}$ column and methanol-10 mM ammonium acetate buffer (pH 9.42 with ammonium water), as mobile phase. Rabeprazole produced a protonated precursor ion [$(M+H)^+$] at m/z 360.10 and corresponding product ion at m/z 242.21. Internal standard produced a protonated precursor ion [$(M+H)^+$] at 346.09 and corresponding product ion at m/z 198.09. This method showed linear response over the concentration range of $1{\sim}500\;ng/mL$ with correalation coefficient greater than 0.99. The lower limit of quantitation (LLOQ) using 0.2 mL plasma was 1 ng/mL, which was sensitive enough for pharmacokinetics studies. The method was specific and validated with a limit of quantitation of 1 ng/mL. The intra-day and inter-day precision and accuracy were acceptable for all samples including the LLOQ. The applicability of the method was demonstrated by analysis of plasma after administration of a single 10 mg dose to 36 healthy subject. From the plasma rabeprazole concentration versus time curves, the mean $AUC_t$ (The area under the plasma concentration-time curve from time 0 to 12 hr ) was $691.36{\pm}321.88\;ng{\cdot}hr/mL$, $C_{max}$ (maximum plasma drug concentration) of $353.21{\pm}131.52\;ng/mL$ reached $3.4{\pm}1.1\;hr$ after adiministration. The mean biological half-life of rabeprazole was $1.37{\pm}0.75\;hr$. Based on the results, this simple method could readily be used in pharmacokinetics studies.

• 한국대기환경학회지
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• 제1권1호
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• pp.9-15
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• 1985

For the purpose of obtaining the index that represents the contaminated status due to polychlorinated biphenyls (PCB) in the human body, the authors investigated the contents of PCB in the plasma of 183 subjects who were not exposured to the massive amount of PCB occupationaly in the past. The obtained results were as follows; 1. The mean contents of PCB in plasma were 3.35 $\pm$ 1.48 ppb in male and 3.04 $\pm$ 1.06 ppb in female. $Cl_4$ and $Cl_3$ were the main isomers in both sexes. 2. The distribution of total-PCB by the age group was showed increasing tendency with the age in both sexes. 3. The tendency of freqyency distribution of total-PCB level were skewed to the higher level in malo and skewed to the lower level in female. 4. There was satistically significant interrelationship between age and total-PCB in plasma in both sexes.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.105-105
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• 2003

A rapid and reproducible high performance liquid chromatographic assay of prazosin in human plasma was developed. After addition of internal standard (IS, terazosin hydrochloride) and alkalization of the plasma, the drug and IS were extracted into t-butylmethylether. The organic phase was back-extracted into 0.05% phosphoric acid and 50 ${\mu}\ell$ of the acid solution was injected into a reverse-phase C18 column with a mobile phase consisting of water : acetonitrile : triethylamine = 75 : 25 : 0.1 (pH 5.0). The samples were detected utilizing a fluorescence detector. A

• Archives of Pharmacal Research
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• 제23권5호
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• pp.441-445
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• 2000

Achiral-chiral column switching HPLC assay was developed to allow the separation and quantification of the enantiomers of terbutaline in human plasma by means of fluorescence detection. Plasma samples were prepared by solid-phase extraction with sep-pak silica, followed by HPLC assay. The enantiomers of terbutaline and the internal standard were separated from the biological matrix on a silica column, and the two enantiomers were resolved and quantified on a Sumichiral OA-4900 column. The two columns were connected by a switching valve equipped with silica trap column, The trap column was used to concentrate the terbutaline in the eluent from the achiral column before back flushing onto the chiral phase. For each enantiomers, the assay was linear between 2.5-125 ng/$m\ell$ (r=0.9999) and detection limit was 1.0 ng/$m\ell$ .

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.401.2-401.2
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• 2002

To study the pharmacokinetics of triflusal, more reliable and sensitive analytical method of triflusal in plasma sample was developed. Analytical method of triflusal in human plasma was developed using semi-microbore HPLC equipped with automated column switching system. p- Toluic acid, which is structural analogue of triflusal. was used as an internal standard and 2 M HCI was employed as a stabilizer. The load phase and mobile phase were prepared using acetonitrile and 20 mM $KH_{2}PO_{4}$ with the volume ratios of 10:90 (pH 2.5) and 43:57 (pH 2.3), respectively. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.224.1-224.1
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• 2003

A sensitive and selective liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the determination of beraprost in human plasma. Plasma samples were transferred into 96-well OASIS HLB extraction plate using an automated sample handling system and the drugs were eluted with methanol. The eluents were then evaporated and reconstituted with water. All sample transfer and solid-phase extraction (SPE) was automated through the application of both the PerkinElmer MultiPROBE II HT and TOMTEC Quadra 96 workstation. (omitted)